■Faculty | Department of Mechanical Engineering / Graduate School of Science and Engineering Research |

■Position | Professor |

■Degree | |

■Commentator Guide | https://www.kindai.ac.jp/meikan/453-sakata-seiichirou.html |

■URL | |

Last Updated :2020/04/03

- 2017 04 , - 現在, Professor, Faculty of Science and Engineering, Kindai University
- 2012 04 , - 2017 03 , Associate Professor, Department of Mechanical Engineering, Faculty of Science and Engineering, Kinki University
- 2007 04 , - 2012 03 , Interdisciplinary Faculty of Science and Engineering, Shimane University
- 2003 04 , - 2007 03 , Interdisciplinary Faculty of Science and Engineering, Shimane University
- 2000 04 , - 2003 03 , Interdisciplinary Faculty of Science and Engineering, Shimane University

- Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Machine materials and mechanics

- Stochastic Elastic Property Evaluation with Stochastic Homogenization Analysis of a Resin Structure made using the FDM method, Sei-ichiro Sakata, Yuki Yamauchi, ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems Part B: Mechanical Engineering, ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems Part B: Mechanical Engineering, Accepted(3), 030901-1 - 030901-12, Sep. 2019 , Refereed
- Stochastic Elastic Property Evaluation with Stchastic Homogenization Analysis of a Resin Structure Made Using the Fused Deposition Modeling Method, Sei-ichiro Sakata, ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems Part B: Mechanical Engineering, ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems Part B: Mechanical Engineering, Sep. 2019 , Refereed
- A local sensitivity based multiscale stochastic stress analysis of a unidirectional fiber reinforced composite material considering random location variation of multi fibers, Sei-ichiro Sakata, Takuro Sakamoto, ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems Part B: Mechanical Engineering, ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems Part B: Mechanical Engineering, 5(3), 030902-1 - 030902-12, Sep. 2019 , Refereed
- Piezoelectric control of a transient thermoelastic displacement distribution in a composite disk, Sei-ichiro Sakata, Journal of Thermal Stresses, Journal of Thermal Stresses, 41(10-12), 1558 - 1576, Oct. 2018 , Refereed
- A successive perturbation-based multiscale stochastic analysis method for composite materials, Sei-ichiro Sakata, Itaru Torigoe, Finite Elements in Analysis and Design, Finite Elements in Analysis and Design, 102-103, 74 - 84, Sep. 2015 , Refereed
- Analysis of complicated one-dimensional stress oscillation behaviour in a functionally graded material plate, F. Ashida, S. Sakata, T. Ohtsuka, ZAMM, ZAMM, 95(2), 184 - 192, Feb. 2015 , Refereed
- Stochastic analysis of laminated composite plate consdering stochastic homogenization problem, S. Sakata, K. Okuda, K. Ikeda, Frontiers of Structural and Civil Engineering, Frontiers of Structural and Civil Engineering, 2015 , Refereed
- Stochastic homogenization analysis of a porous material with the perturbation method considering a microscopic geometrical random variation, S. Sakata, F. Ashida, K. Ohsumimoto, International Journal of Mechanical Sciences, International Journal of Mechanical Sciences, 77, 145 - 154, Dec. 2013 , Refereed
- Multiscale Stohcastic Stress Analysis of a Porous Material with the Perturbation-Based Stochastic Homogenization Method for a Microscopic Geometrical Random Variation, Journal of Computational Science and Technology, Journal of Computational Science and Technology, 7(1), 99 - 112, Jun. 2013
- A Multiscale Stohcastic Stress Analysis of a Heterogeneous Material considering Nonuniform Microscopic Random Variation, Journal of Computational Science and Technology, Journal of Computational Science and Technology, 7(2), 137 - 147, Jun. 2013
- A Stochastic Homogeniazation Analysis for a Thermoelastic Problem of a Unidirectional Fiber-Reinforced Composite Material with the Homogenization Theory, Journal of Thermal Stresses, Journal of Thermal Stresses, 36(5), 405 - 425, Apr. 2013
- Inverse Stochastic Homogenization Analysis for a Particle-Reinforced Composite Material with the Perturbation-Based Approach, SAKATA Sei-ichiro, SHIMIZU Yoshitaka, TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A, TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A, 79(802), 789 - 801, 2013 Summary:This paper discusses the inverse stochastic homogenization analysis for a particle-reinforced composite material. The homogenization analysis is performed with the homogenization theory, and the stochastic analysis is performed with the perturbation-based approach. In order to analyze the inverse stochastic homogenization problem, which aims to identify the coefficient of variances of the randomly varied elastic properties of component materials from the probabilistic characteristics of the homogenized elastic properties, the inverse stochastic homogenization method with the perturbation-based technique is proposed. The probabilistic properties of the homogenized elastic properties, which are obtained from an experiment or the Monte-Carlo simulation, are assumed to be known and used in the inverse stochastic homogenization analysis. The inverse stochastic homogenization problems with considering a single- or multi-variation of the elastic properties of the component materials are solved, and from the numerical results, accuracy and effectiveness of the proposed method are discussed.
- Stochastic Homogenization Analysis of a Particle Reinforced Composite Material using an Approximate Monte-Carlo Simulation with the Weighted Least Square Method, Journal of Computatinoal Science and Technology, Journal of Computatinoal Science and Technology, 7(1), 1 - 11, Jan. 2013
- Optimum Structure Design of a Multilayer Piezo-Composite Disk for Control of Thermal Stress, Journal of Thermal Stresses, Journal of Thermal Stresses, 35(9), 805 - 819, Jul. 2012
- A Microscopic failure probability analysis of a unidirectional fiber reinforced composite material via a multiscale stochastic stress analysis for a microscopic random variation of an elastic property, Computational Materials Science, Computational Materials Science, 62, 35 - 46, Jun. 2012
- Hierarchical Stochastic Homogenization Analysis of Particle Reinforced Composite Materials considering Non-uniform Distribution of Microscopic Random Quantities, Computational Mechanics, Computational Mechanics, 48, 529 - 540, Nov. 2011
- Kriging-based Convex Subspace Single Linkage Method with Path-based Clustering Technique for Approximation-based Global Optimization, Structural and Multidisciplinary Optimization, Structural and Multidisciplinary Optimization, 44(9), 393 - 408, Sep. 2011
- Perturbation-based Stochastic Microscopic Stress Analysis of a Particle Reinforced Composite Material considering Microscopic Uncertainty in Material Properties, Journal for Multiscale Computational Engineering, Journal for Multiscale Computational Engineering, 9(4), 409 - 423, Aug. 2011
- Inverse Stochastic Homogenization Analysis for a Particle-Reinforced Composite Material with the Monte Carlo Simulation, Journal for Multiscale Computational Engineering, Journal for Multiscale Computational Engineering, 9(4), 409 - 423, Aug. 2011
- Integral Estimation with the Ordinary Kriging Method using the Gaussian Semivariogram Function, International Journal for Numerical Methods in Biomedical Engineering, International Journal for Numerical Methods in Biomedical Engineering, 27, 1235 - 1251, Aug. 2011
- Control of Transient Thermal Stress in a Piezo-composite Disk, International Journal of Theoretical and Applied Multiscale Mechanics, International Journal of Theoretical and Applied Multiscale Mechanics, 2(1), 19 - 37, Jun. 2011
- Hierarchical Stochastic Homogenization Analysis of a Short-Fiber Reinforced Composite Material Considering a Non-Uniform Microscopic Random Variation, SAKATA Sei-ichiro, ASHIDA Fumihiro, TANAKA Ryuta, TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A, TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A, 77(783), 1945 - 1955, 2011 Summary:This paper discusses a stochastic homogenization analysis problem of a unidirectionally aligned short fiber reinforced composite material considering a uniform and/or non-uniform random variation of a microscopic quantity such as a material property or volume fraction of a microstructure. The homogenization analysis is performed with the homogenization theory and the equivalent inclusion method, and the stochastic analysis is performed with the perturbation-based method. In order to analyze the stochastic homogenization problem considering a periodic non-uniform microscopic random variation of the microscopic quantity, the hierarchical stochastic homogenization analysis procedure is proposed. As an example, the stochastic homogenization problems considering a non-uniform random variation of Young's modulus of resin and volume fraction of fiber are solved. From the numerical results, influence of the non-uniformity of the microscopic random variation is discussed. Also, from comparison between the results obtained with the proposed method and the Monte-Carlo simulation, accuracy of the proposed approach for the stochastic homogenization analysis of the short fiber reinforced composite material is discussed.
- Inverse Problem of a Piezothermoelastic Cylinder subject to Transient Heating, Journal of Thermal Stresses, Journal of Thermal Stresses, 33(7), 706 - 718, Jul. 2010
- Identification of a Microscopic Randomness of a Particle Reinforced Composite Material with Monte-Carlo Simulation and Inverse Homogenization Analysis, Materials Science and Engineering, Materials Science and Engineering, 10(12186), 1 - 9, Jul. 2010
- Stochastic Multiscale Stress Analysis via Identification of Microscopic Randomness, Materials Science and Engineering, Materials Science and Engineering, 10(12203), 1 - 8, Jul. 2010
- Optimum Design of Electrode Arrangements in a Multilayer Piezo-composite Disk for Control of Thermal Stresses, Journal of Computational Science and Technology, Journal of Computational Science and Technology, 4(2), 77 - 88, Jun. 2010
- Stabilization of Parameter Estimation for Kriging-based Approximation with Empirical Semivariogram, Computer Methods in Applied Mechanics and Engineering, Computer Methods in Applied Mechanics and Engineering, 199(25-28), 1710 - 1721, May 2010
- Stochastic Analysis of Microscopic Stress in Fiber Reinforced Composites Considering Uncertainty in a Microscopic Elastic Property, Journal of Solid Mechanics and Materials Engineering, Journal of Solid Mechanics and Materials Engineering, 4(5), 568 - 577, May 2010
- Stochastic Homogenization Analysis for Thermal Expansion Coefficients of Fiber Reinforced Composites using the Equivalent Inclusion Method with Perturbation-based Approach, Comupters & Structures, Comupters & Structures, 88, 458 - 466, Apr. 2010
- First Order Peturbation-based Stochastic Homogeniation Analysis for Short Fiber Reinforced Composite Materials, Journal of Solid Mechanics and Materials Engineering, Journal of Solid Mechanics and Materials Engineering, 4(3), 446 - 459, Mar. 2010
- Comparative Study on Gradient and Hessian Estimation using the Kriging Mehtod and Neural Network Approximation, Mathematical and Computer Modelling, Mathematical and Computer Modelling, 51(3-4), 309 - 319, Mar. 2010
- Influence of Random Variation in Volume Fraction of Fiber on Stochastic Property of Equivalent Elastic Property of Unidirectional Fiber Reinforced Composite Material, Journal of Solid Mechanics and Materials Engineering, Journal of Solid Mechanics and Materials Engineering, 4(3), 435 - 445, Mar. 2010
- Approximate Global Optimization with Convexity Estimation of Response Surface using Kriging Method, Structural and Multidisciplinary Optimization, Structural and Multidisciplinary Optimization, 40(1-6), 417 - 431, Jan. 2010
- Perturbation-based Successive Approximate Topology Optimization for a Displacement Minimization Problem, Computer Methods in Applied Mechanics and Engineering, Computer Methods in Applied Mechanics and Engineering, 199(1-4), 148 - 157, Dec. 2009
- Stochastic Homogenization Analysis for Particle Reinforced Composites Using First-Order Perturbation Based Equivalent Inclusion Method, SAKATA Sei-ichiro, ASHIDA Fumihiro, KOJIMA Tomoyuki, Transactions of the Japan Society of Mechanical Engineers. A, Transactions of the Japan Society of Mechanical Engineers. A, 75(756), 1015 - 1020, Aug. 25 2009 Summary:This paper describes a method for stochastic homogenization analysis of a particle reinforced composite material. Since it is difficult to apply the homogenization-based perturbation method using the finite element method to a stochastic homogenization problem with considering a microscopic geometrical random variation in a microstructure, the equivalent inclusion method is used for the perturbation-based stochastic homogenization analysis. In using the equivalent inclusion method, each perturbation term for a random variation in a material property, size of inclusions or their volume fraction can be computed analytically. This fact shows applicability to apply the proposed method to a stochastic homogenization problem considering the microscopic geometrical random variation. At first, formulations for the proposed method are introduced. Next, the proposed method is applied to several kinds of numerical examples. From the numerical results, validity and accuracy of the proposed method are confirmed.
- Ns-Kriging based Microstructural Optimization Applied to Minimizing Stochastic Variation of Homogenized Elasticity of Fiber Reinforced Composites, Structural and Multidisciplinary Optimization, Structural and Multidisciplinary Optimization, 38(5), 443 - 453, Jun. 2009
- On Perturbation-based Stochastic Homogenization Analysis for a Homogenized Equivalent Elastic Constant of FRP using the Equivalent Inclusion Method, Journal of Solid Mechanics and Materials Engineering, Journal of Solid Mechanics and Materials Engineering, 3(3), 552 - 562, Mar. 2009
- Stochastic Homogenization Analysis on Elastic Properties of Fiber Reinforced Composites using the Equivalent Inclusion Method and Perturbation Method, International Journal of Solids and Structures, International Journal of Solids and Structures, 45(25-26), 6553 - 6565, Dec. 2008
- Proposition of a First-Principles Aided Triple-Scale Analysis for Biocompatible Piezoelectric Thin Films, UETSUJI Yasutomo, HWANG Hwishim, SAKATA Sei-ichiro, TSUCHIYA Kazuyoshi, NAKAMACHI Eiji, Transactions of the Japan Society of Mechanical Engineers. A, Transactions of the Japan Society of Mechanical Engineers. A, 74(747), 1405 - 1410, Nov. 25 2008 Summary:A computational scheme of first-principles aided triple-scale analysis based on a process crystallography was proposed to design biocompatible piezoelectric thin films fabricated on substrate. To predict the crystal morphology of thin film such as preferred orientations and their ratio, the structural stability of all comformations of crystal cluster on substrate was evaluated by employing pseudo-potential method in density functional theory. Then, the predicted crystal morphology was introduced into micro structure and macro homogenized properties of piezoelectric thin film were estimated through dual-scale finite element analysis based on crystallographic homogenization theory. From the application to the existing biocompatible piezoelectric BaTiO_3 thin films fabricated on SrTiO_3 (110), SrTiO_3 (001) and MgO(100), computational results of the preferred orientations of microstructure and the homogenized dielectric constants of macrostructure had good correlation with experimental ones. Additionally, the proposed computation was applied to a new biocompatible piezoelectric MgSiO_3 thin film, which has been found by first-principles calculations in our previous studies. As a result, the computation indicated that Cr(110) substrate is most suitable for stable crystal growth of MgSiO_3 orientated to [101] direction and it outputs the high piezoelectric stress constants e_<33>=5.39C/m^2 and e_<31>=-3.64C/m^2.
- Structure Design of a Piezoelectric Composite Disk for Control of Thermal Stress, ASME Journal of Applied Mechanics, ASME Journal of Applied Mechanics, 75(61009), 1 - 8, Nov. 2008
- Microstructural Design of Composite Materials using Fixed-grid Modeling and Noise-resistant Smoothed Kriging-based Approximate Optimization, Structural and Multidisciplinary Optimization, Structural and Multidisciplinary Optimization, 36(3), 273 - 287, Sep. 2008
- Prediction Accuracy for Response Surfaces Generated Using Noisy Data, TAKEDA Norio, SAKATA Sei-ichiro, Transactions of the Japan Society of Mechanical Engineers. A, Transactions of the Japan Society of Mechanical Engineers. A, 74(743), 1031 - 1039, Jul. 25 2008 Summary:Response surfaces generated by using an artificial neural network or a Kriging model can approximate multimodal responses and the responses of multi-variable functions, even if the prior information used in creating the surfaces contains noises. To prevent the response surfaces from fitting to the noises in the prior information, regularization methods are applied. The Bayesian regularization method works well with an artificial neural network, and the improved nugget effect method can be effectively applied to the regularization of an ordinary Kriging model. Which response surface model to select depends on the amount of prior information and the number of variables in the response function. The Kriging model generates a more accurate response surface with a smaller amount of prior information than the artificial neural network does. On the other hand, the artificial neural network is more effective for approximating the response of a multivariable function than the Kriging model. As a result, we can apply the response surface method to find the variables that ensure the optimum response of a function. This may increase the opportunities for using optimization techniques in the practical design process.
- Approximate Structural Optimization using Kriging Method and Digital Modeling Technique considering Noise in Sampling Data, Computers and Structures, Computers and Structures, 86(13-14), 1477 - 1485, Jul. 2008
- Crystal Growth Prediction by First-Principles Calculations for Epitaxial Piezoelectric Thin Films, UETSUJI Yasutomo, HWANG Fishim, SAKATA Sei-ichiro, TSUCHIYA Kazuyoshi, NAKAMACHI Eiji, Transactions of the Japan Society of Mechanical Engineers. A, Transactions of the Japan Society of Mechanical Engineers. A, 74(741), 763 - 769, May 25 2008 Summary:A computational prediction scheme of preferred orientations on various substrates by first principles calculation was proposed to design epitaxial piezoelectric thin film fabricated by sputtering, chemical vapor deposition and molecular beam epitaxy processes. At first, we computed epitaxial strain in piezoelectric thin film caused by lattice mismatch with substrate. When epitaxial strain is applied to crystal unit cell, total energy was evaluated by employing pseudo-potential method in density functional theory. Then, preferred orientations were predicted in view of stability of crystal cluster with various conformations on substrate. From application to BaTiO_3 thin films fabricated on SrTiO_3(110), SrTiO_3(001), MgO(100) and LaTiO_3(001), calculations indicated that total energy increment of cluster was available to evaluate the possibility of crystal growth. Calculational results of preferred orientations had good correlation with experimental.
- Kriging-based Approximate Stochastic Homogenization Analysis for Composite Material, Computer Methods in Applied Mechanics and Engineering, Computer Methods in Applied Mechanics and Engineering, 197(21-24), 1953 - 1964, Apr. 2008
- Control of Overfitting in Hierarchical Neural Networks with DFP Formula, ASHIDA Fumihiro, SAKATA Sei-ichiro, KAWAGUCHI Takahisa, Transactions of the Japan Society of Mechanical Engineers. A, Transactions of the Japan Society of Mechanical Engineers. A, 74(739), 406 - 411, Mar. 25 2008 Summary:This paper discusses a method for avoidance of overfitting which occurs during the training process of hierarchical neural networks with DFP updating formula. In comparison with a case of employing the back propagation algorithm for the updating formula, the training with the DFP formula finishes very quickly, but a frequency of the overfitting increases. In order to decrease the frequency, we have improved the algorithm so that the approximate inverse Hessian matrix is initialized at every hundred learning steps. The improved algorithm is applied to approximations of a sinc function with a variable as well as of a design space of an optimization problem with two variables. An repetition interval of the training procedure at which the approximate inverse Hessian matrix should be initialized is investigated. The interval exerts little influence upon the probability of obtaining good training results, whereas the probability of obtaining good testing results depends on the interval. As a result, the overfitting can be avoided successfully if the appropriate interval is maintained.
- Influence of Uncertainty in Microscopic Material Property on Homogenized Elastic Property of Unidirectional Fiber Reinforced Composites, Theoretical and Applied Mechanics Japan, Theoretical and Applied Mechanics Japan, 56, 67 - 76, Mar. 2008
- One-Dimensional Generalized Thermoelastic Analysis of a Two-Layered Composite Thin Film with Damping, ASHIDA Fumihiro, SUMI Naobumi, SAKATA Sei-ichiro, MAEDA Mayuko, Transactions of the Japan Society of Mechanical Engineers. A, Transactions of the Japan Society of Mechanical Engineers. A, 74(738), 208 - 215, Feb. 25 2008 Summary:This paper deals with one-dimensional generalized thermoelasticity in a composite thin film constructed of a piezoceramic layer and a structural layer , when damping effect is taken into account. The film is initially at reference temperature and subjected to a ramp heating on the free surface of the piezoceramic layer. By applying Lord and Shulman's theory the governing equations for the temperature changes, heat fluxes, particle velocities, axial stresses and electric field intensity are reduced to a system of nine first-order partial differential equations. This problem has been numerically analyzed by employing the method of characteristics. Finally, the effect of a damping coefficient on time histories of the temperature changes, axial stresses and electric field intensity are illustrated graphically.
- Three-dimensional Stochastic Analysis using a Perturbation-based Homogenization Method for Elastic Properties of Composite Material considering Microscopic Uncertainty, International Journal of Solids and Structures, International Journal of Solids and Structures, 45(3-4), 894 - 907, Feb. 2008
- Stochastic Response Analysis of FRP using the Second-order Perturbation-based Homogenization Method, Journal of Solid Mechanics and Materials Engineering, Journal of Solid Mechanics and Materials Engineering, 2(1), 70 - 81, Jan. 2008
- Control of Thermoelastic Deformation in a Smart Composite Disk by a Stepwise Applied Electric Potential Distribution, Acta Mechanica, Acta Mechanica, 195(1-4), 13 - 26, Jan. 2008
- Control of Thermal Stress in a Two-Layered Piezoelectric Composite Disk, ASHIDA Fumihiro, SAKATA Sei-ichiro, MATSUMOTO Kouhei, Transactions of the Japan Society of Mechanical Engineers. A, Transactions of the Japan Society of Mechanical Engineers. A, 73(734), 1164 - 1170, Oct. 25 2007 Summary:This paper deals with a stress control problem of a composite disk consisting of a transversely isotropic structural layer onto which a piezoelectric layer of crystal class 6mm is perfectly bonded. A number of electrodes are arranged concentrically on the top surface of the piezoelectric layer. When a heating temperature distribution acts on the bottom surface of the composite disk, the maximum thermal stress in the structural layer can be controlled by applying an appropriate electric potential to each electrode. The applied electric potentials are determined by using the quasi-Newton method based on the BFGS updating formula in the case where stress constraints are imposed on the piezoelectric layer. The exterior penalty function method is employed in order that the optimization problem with stress constraints is transformed to that without stress constraints. Numerical calculations have been carried out for a composite disk which consists of a CFRP layer and a cadmium selenide layer. Finally, numerical results are shown in tables and figures.
- Control of Thermal Stress in a Piezo-Composite Disk, Journal of Thermal Stresses, Journal of Thermal Stresses, 30(9-10), 1025 - 1040, Oct. 2007
- Hybrid Approximation Algorithm with Kriging and Quadratic Polynomial-based Approach for Approximate Optimization, International Journal for Numerical Methods in Engineering, International Journal for Numerical Methods in Engineering, 70(6), 631 - 654, Jul. 2007
- Optimum Design of a Piezo-Composite Disk for Control of Thermoelastic Displacement Distribution, Journal of Thermal Stresses, Journal of Thermal Stresses, 30(6), 559 - 586, Jun. 2007
- On Applying Kriging-Based Approximate Optimization to Inaccurate Data, Computer Methods in Applied Mechanics and Engineering, Computer Methods in Applied Mechanics and Engineering, 196(13-16), 2055 - 2069, Mar. 2007
- Control of Thermally-Induced Vibration in a Composite Beam with Damping Effect, Journal of Thermal Stresses, Journal of Thermal Stresses, 29(2), 139 - 152, Jun. 2006
- Control of Temperature-induced Plate Vibrations based on Speed Feedback, Journal of Thermal Stresses, Journal of Thermal Stresses, 29(6), 585 - 606, Jun. 2006
- Control of Thermoelastic Displacement in a Two-Layered Composite Disk by Applying Stepwise Electric Potentials, ASHIDA Fumihiro, SAKATA Sei-ichiro, YOSHIDA Shinji, Transactions of the Japan Society of Mechanical Engineers. A, Transactions of the Japan Society of Mechanical Engineers. A, 72(714), 239 - 246, Feb. 25 2006 Summary:This paper discusses a displacement control problem in a two-layered composite disk consisting of a transversely isotropic structural layer onto which a piezoceramic layer of crystal class 6mm is perfectly bonded. It is considered that some electrodes are concentrically arranged on the top surface of the disk. When an axisymmetric heating temperature acts on the bottom surface of the disk, the thermally induced displacement distribution on the bottom surface is controlled by applying a stepwise electric potential distribution to the top surface. The voltage which could be applied to each electrode is determined by optimization so that the displacement over the bottom surface of the disk has a desired distribution.
- Approximate Optimization Method for Dsign of a Multi-Layered Piezoceramic Plate, ASHIDA Fumihiro, SAKATA Sei-ichiro, HORINOKUCHI Naokazu, Transactions of the Japan Society of Mechanical Engineers. A, Transactions of the Japan Society of Mechanical Engineers. A, 70(693), 717 - 723, May 25 2004 Summary:The present paper discusses an approximate optimization method using the neural network in order to design a multi-layered composite plate constructed of an isotropic structural layer and multiple piezoceramic layers of class 6mm. The puropse of this design is to determine the ticknesses of the piezoceramic layers, such that the maximum value of the electric potential distribution which controls the thermal displacement on the surface of the structural layer is minimized subject to stress constraints. Instead of the back propagation method, the quasi-Newton method is employed for an updating formula of the connection weights. By restricting the normalization range of the training data, total execution time necessary to the training process are remarkably reduced. Thus, performance of the learning algorithm is greatly improved. Applying the improved learning algorithm to the design of the multi-layered composite plate, fairly good results for the approximate optimization are obtained.
- An Efficient Algorithm for Kriging Approximation and Optimization with Large-scale Sampling Data, Computer Methods in Applied Mechanics and Engineering, Computer Methods in Applied Mechanics and Engineering, 193(3-5), 385 - 404, Jan. 2004
- Optimum Design of a Multi-Layered Composite Plate Using Neural Networks, Journal of Thermal Stresses, Journal of Thermal Stresses, 26(11-12), 1137 - 1150, Dec. 2003
- Control of Transient Deformation in a Heated Intelligent Composite Disk, Smart Materials and Structures, Smart Materials and Structures, 12, 825 - 835, Oct. 2003
- Application of a Gradient Method to Approximate Structural Optimization Using Kriging Method, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, Transactions of the Japan Society of Mechanical Engineers. C, Transactions of the Japan Society of Mechanical Engineers. C, 69(681), 1209 - 1215, May 25 2003 Summary:This paper describes an approximate structural optimization method by using the Kriging method and an optimization method using gradient components of an objective function. The Kriging method requires an assumption on semivariogram model, an approximated surface can be generated without an assumption on an order of base function for approximation. In this paper, Gauss model is assumed as a semivariogram. The proposed method consists of two main processes. 0ne is a space approximation process by the Kriging method, and another is an optimization process. In the proposed method, a gradient component on an approximated surface is obtained analytically by using an assumed semivariogram. Some numerical examples are illustrated to evaluate an applicability of the Kriging method to a structural optimization. And to illustrate effectiveness of the proposed method, two structural optimization problems are solved by using the proposed method. Numerical results show effectiveness and validity of the proposed method.
- An Efficient Simultaneous Design of Location and Cross-Sectional Shape of a Frame Structure by an Incline Allocation of Resources Using First Order Sensitivity Analysis, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, HORINOKUCHI Naokazu, Transactions of the Japan Society of Mechanical Engineers. Series C., Transactions of the Japan Society of Mechanical Engineers. Series C., 69(680), 1044 - 1050, Apr. 25 2003
- Development of the Convex Subspace Single-Linkage Algorithm for Nonlinear Optimization Problem with Multicrestedness, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, Transactions of the Japan Society of Mechanical Engineers. C, Transactions of the Japan Society of Mechanical Engineers. C, 69(680), 1037 - 1043, Apr. 25 2003 Summary:This paper describes an optimizing algorithm for a global optimization problem, which has multi-local optimum solutions. 0n structural optimizations, some problems cannot be solved by using nonlinear programming method for convex optimization problem, because those are non-convex problem by complexity of constraint or objective function itself. Therefore, the global optimizing system that makes use of local optimizing procedure is needed for more effective searching in some design problems. The proposed method is to be characterized by using clustering procedure for convex subspaces, which are formed in a local optimizing procedure, and by using Lebesque measurement to evaluate a termination criterion. In order to evaluate the effectiveness of the algorithm, some numerical examples are illustrated
- Eigenfrequency Optimization of Stiffened Plate Using Kriging Estimation, Computational Mechanics, Computational Mechanics, 31, 409 - 418, Apr. 2003
- Structural Optimization Using Kriging Approximation, Computer Methods in Applied Mechanics and Engineering, Computer Methods in Applied Mechanics and Engineering, 192(7-8), 923 - 939, Feb. 2003
- A Layout Optimization of Beam Reinforcements to Decrease Thermal Deformation of Beam Structures, S. Sakata, F. Ashida, M. Zako, Journal of Thermal Stresses, Journal of Thermal Stresses, 25(11), 1081 - 1101, Nov. 2002 , Refereed
- Topology and Detail Geometry Optimization for Beam Structures Using Homotopy Modeling, S. Sakata, F. Ashida, M. Zako, Computer Methods in Applied Mechanics and Engineering, Computer Methods in Applied Mechanics and Engineering, 191(39-40), 4279 - 4293, Aug. 2002 , Refereed
- Transient Plane-Stress Response of a Piezothermoelastic Circular Disk, F. Ashida, T.R. Tauchert, S. Sakata, Journal of Thermal Stresses, Journal of Thermal Stresses, 25(7), 627 - 646, Jul. 2002 , Refereed
- Inverse Transient Thermoelastic Problem for a Composite Circular Disk, F. Ashida, S. Sakata, T.R. Tauchert, Y. Yamashita, Journal of Thermal Stresses, Journal of Thermal Stresses, 25(5), 431 - 455, May 2002 , Refereed
- Analysis of Transient Plane Thermoelastic Field in a Piezoceramic Circular Plate, F. Ashida, S. Sakata, Theoretical and Applied Mechanics Japan51, Theoretical and Applied Mechanics Japan51, 51, 259 - 266, Mar. 2002 , Refereed
- Applications of CSSL Method to Multi-peaked Structural Optimization Problem, S. Sakata, F. Ashida, M. Zako, Theoretical and Applied Mechanics Japan, Theoretical and Applied Mechanics Japan, 51, 335 - 341, Mar. 2002 , Refereed
- Analysis of Plane Thermoelastic Field in a Piezoceramic Circular Plate, F. Ashida, S. Sakata, Theoretical and Applied Mechanics, Theoretical and Applied Mechanics, 50, 49 - 55, Mar. 2001 , Refereed
- Layout Optimization of Additional Elements to Create New Composite Materials by Microscopic Structural Design Using CSSL Method, S. Sakata, F. Ashida, M. Zako, Theoretical and Applied Mechanics, Theoretical and Applied Mechanics, 50, 33 - 40, Mar. 2001 , Refereed
- Deep-Drawing Analysis of Knitted Composite Materials Considering the Geometrical Non-linearity of Knitted Structures, ZAKO Masaru, FUJIHARA Makoto, CHENG Lim Teik, SAKATA Seiichiro, 繊維機械学会誌 = Journal of the Textile Machinery Society of Japan, 繊維機械学会誌 = Journal of the Textile Machinery Society of Japan, 54(2), 41 - 48, Mar. 2001
- Geometrical Non-linearity of Textile Composites in Large Deformation, T.C. Lim, M. Zako, S. Sakata, S. Ramakrishna, Advanced Composite Letters, Advanced Composite Letters, 9(4), 257 - 267, Jul. 2000 , Refereed

- Multiscale Modeling and Uncertainty Quantification of Materials and Structures, S. Sakata, M. Papadrakakis, G. Stefanou, 分担執筆, Adaptive Strategy for Stochastic Homogenization and Multiscale Stocahstic Stress Analysis (pp.51-66), Springer, 2014
- Encyclopedia of Thermal Stresses, S. Sakata, R. Hetnarski, 分担執筆, Optimization of Thermoelastic Structures(pp.3520-3530), Springer, 2014
- Mechanics of Electromagnetic Material Systems and Structures, F. Ashida, T.R. Tauchert, S. Sakata, Y. Yamashita, Y.Shindo, 分担執筆, pp.271-279, WIT press, 2003

- An Adaptive Strategy for the Stochastic Homogenization and the Multiscale Stochastic Stress Analysis, IUTAM Symposium on Multiscale modeling and uncertainty quantification of materials and structures, 2013 09 , IUTAM Symposium on Multiscale modeling and uncertainty quantification of materials and structures
- Control of Transiengt Thermal Stress in a Smart Piezo-Composite Disk, Thernal Stresses 2013, 2013 06 , Thernal Stresses 2013
- Optimum Stricture Design of a Multilayer Piezo-composite Disk for Control of Thermal Stress, ICTAM 2012, 2012 08 , ICTAM 2012
- Complicated Stress Oscillations Induced in a Functionally Graded Material Film, ICTAM 2012, 2012 08 , ICTAM 2012
- Inverse Stochastic Homogenization Analysis of a Particle Reinforced Composite Material with a Function Approximation Approach, 10th World Congress on Computational Mechanics, 2012 07 , 10th World Congress on Computational Mechanics
- Efficient Optimum Design of a Piezoelectric Composite Disk for Thermal Stress Control, TS2011, 2011 06 , TS2011
- Stochastic Homogenization Analysis on Thermoelastic Properties of a Composite Material Considering Material Property Variations of Component Materials, TS2011, 2011 06 , TS2011
- Preprocessing for the Kriging-based Approximate Optimization, WCSMO9, 2011 06 , WCSMO9
- 204 Stabilization of Parameter Identification with Empirical Semivariogram for Kriging Estimation, Sakata Sei-ichiro, Ashida Fumihiro, 2010 12 09 Summary:This paper presents a stabilization technique for semivariogram parameter identification process used in the Kriging method. In this study, the empirical semivariogram-based parameter identification process is employed. In this case, numerical instability of the parameter identification process is sometimes observed, and a stabilization technique for this problem is proposed. In this paper, outline of the Kriging estimation and instability of the parameter identification process are explained at first. Next, the proposed method is described. With some numerical examples, effectiveness of the proposed method is illustrated.
- Inverse Thermoelasitc Problem of a Piezoceramic Composite Hollow Cylinder, ACMFMS2010, 2010 10 , ACMFMS2010
- Efficient Optimum Design of Electrode Arrangements in a Multilayer Piezo-composite Disk for Control of Thermal Stress, ACMFMS2010, 2010 10 , ACMFMS2010
- Design of Electrodes in a Two Layered Piezoelectric Composite Disk for Control of Thermal Stress, ACMFMS2010, 2010 10 , ACMFMS2010
- Stochastic Homogenizaion Analysis of a Porous Material Manufactured with a Rapid Prototyping, ACMFMS2010, 2010 10 , ACMFMS2010
- S0303-3-5 Stochastic Homogenization Analysis of a Particle Reinforced Composite Material Considering Non-uniform Microscopic Random Variation, SAKATA Sei-ichiro, ASHIDA Fumihiro, TANAKA Ryuta, 2010 09 04 Summary:This paper proposes a new approach for stochastic homogenization analysis of a particle reinforced composite material considering a random variation of an elastic property of component materials. Especially, a non-uniform microscopic random variation is taken into account. In order to analyze a stochastic homogenization problem considering a non-uniformly distributed random variation, a hierarchical modeling with an intermediate scale is introduced. In order to investigate validity of the proposed approach, stochastic homogenization analysis of a glass particle reinforced composite material is performed. From the numerical results, accuracy of the proposed approach is discussed.
- S0303-2-3 Material Design of a Multi-layered Piezoelectric Composite Disk for Control of Thermal Stress, SUZUKI Hikaru, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2010 09 04 Summary:This paper deals with a control problem of a thermal stress in a multilayer composite circular disk consisting of a structural layer onto which piezoceramic layers with concentrically arranged electrodes are bonded. When a heating temperature distribution acts on the structural layer surface, the maximum thermal stress in the structural layer can be suppressed by applying appropriate voltages which are obtained by solving a linear programming problem. Material properties of each piezoelectric layer are determined in order to maximize the suppression ratio of the maximum thermal stress when constraints are imposed on stresses in piezoceramic layers. Finally, obtained numerical results are shown in a figure and a table.
- S0303-2-2 Analysis of a Generalized Magneto-thermoelastic Problem of a Thin Film with Damping, SUZUKI Yuuya, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2010 09 04 Summary:In this paper, a thin film subjected to a thermal shock and a magnetic field intensity on one surface is considered. This problem is analyzed based on the Lord and Shulman's theory of generalized thermoelasticity. The governing equations which contain terms of the magnetic field intensity and the viscosity type damping or the resonance type damping are solved by means of the Laplace transform technique. Numerical calculations have been carried out for a copper thin film. With a numerical result, effects of the damping coefficients and the magnetic field intensity on the time history of stress are investigated.
- S0303-2-1 Dynamic Thermal Stresses in a Functionally Graded Film Subjected to a Uniform Heating., OTSUKA Tatsuya, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2010 09 04 Summary:In this paper, a one-dimensional dynamic thermoelastic problem in a functionally graded thin film subjected to a uniform thermal shock on a top surface is analyzed, assuming that material constants are considered to be an exponential function of the position. Solving the governing equations for the temperature and elastic fields by applying Laplace transform technique, the analytical solution for the temperature, displacement, and stress which satisfy the initial and boundary conditions is obtained. Based on the obtained analytical solution, numerical calculations have been carried out and the time history of stress is shown graphically for a long time.
- T0101-3-6 Inverse Stochastic Homogenization Analysis of a Particle Reinforced Composite Material with Monte-Carlo Simulation, SAKATA Seiichiro, ASHIDA Fumihiro, 2010 09 04 Summary:This paper discusses inverse stochastic homogenization analysis to identify a microscopic random variation of a composite material. The inverse stochastic homogenization procedure is performed with the Monte-Carlo simulation and inverse homogenization analysis, and it estimates a random variation of an elastic property of a component material. In this presentation, outline of the proposed procedure is introduced. Also, from several numerical results, validity and effectiveness of the proposed approach are discussed.
- T0101-3-5 Stochastic Microscopic Stress Analysis of a Particle Reinforced Composite Material Considering Microscopic Random Variations in an Elastic Property and Strength of Component Materials, ENYA Kiminori, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2010 09 04 Summary:This paper discusses the fracture probability analysis of a particle reinforced composites. As random variables, elastic property and strength of a component material are considered. It is assumed that an elastic property of a component material is randomly distributed according to the normal distribution, and the strength distributes according to the Weibull distribution. The random variation of the microscopic stresses are computed using the perturbation-based multiscale stress analysis method. With the numerical results, influence of the random variation of an elastic property on fracture probability is discussed.
- Stochastic Microscopic Stress Analysis of a Composite Material via Multiscale Analysis consdering Microscopic Uncertainty, FDM2010, 2010 09 , FDM2010
- An Improved KCSSL Method for Approximate Global Optimization with Convex-Path Estimation, CJK-OSM6, 2010 06 , CJK-OSM6
- Stochastic Homogeniation Analysis of a Particle Reinforced Composite Material Consirering Non-uniform Random Variation of a Microscopic Quantity, Mesomech2010, 2010 05 , Mesomech2010
- Control of Transient Thermal Stress in a Piezo Composite Disk, Mesomech2010, 2010 05 , Mesomech2010
- 205 Optimization of Electrodes for Controlling Thermal Stress in a Two-Layered Piezoceramic Composite Disk, TOMOZAWA Masanori, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2010 02 24
- 204 Microscopic Stress Analysis of Composite Material Considering Influence of Free Surface, ISHITOBI Ken-ichi, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2010 02 24
- 111 Stochastic Homogenization Analysis of Short Fiber Reinforced Composite Material Considering Non-uniform Distribution of Microscopic Variation, TANAKA Ryuta, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2010 02 24
- 103 Inverse Transient Thermoelastic Problem of a Radially-Polarized Piezoceramic Hollow Cylinder, IGI Yuichi, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2010 02 24
- 102 Inverse Thermoelastic Problem of a Piezoceramic Composite Hollow Cylinder Subject to Asymmetric Heating, SHIGA Takumi, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2010 02 24
- 921 Stochastic Response Analysis on Microscopic Stress in Particle Reinforced Composites using the Stochastic Homogenization Method : In Case of Considering Random Variation in Elastic Property of Component Materials, ENYA Kiminori, SAKATA Sei-ichiro, ASHIDA Fumihiro, The Computational Mechanics Conference, 2009 10 10
- 2408 One-Dimensional Generalized Thermoelastic Analysis of a Piezoelectric Thin Film with Nonlinear Properties, MISU Yosuke, ASHIDA Fumihiro, SAKATA Sei-ichiro, The Computational Mechanics Conference, 2009 10 10
- 2407 One-Dimensional Generalized Thermoelastic Analysis of a Thin Film with Damping : Solutions Obtained Using a Numerical Inverse Laplace Transform Method, FUJIKI Takashi, ASHIDA Fumihiro, SAKATA Sei-ichiro, The Computational Mechanics Conference, 2009 10 10
- 2402 Efficient Control of a Transient Thermal Displacement in a Two-Layered Composite Disk Subject to Stress Constraints, FUJIWARA Hiroki, ASHIDA Fumihiro, SAKATA Sei-ichiro, The Computational Mechanics Conference, 2009 10 10
- 2401 Efficient Control of Transient Thermal Stress in a Two-Layered Piezoelectric Composite Disk, SUGIMOTO Youhei, ASHIDA Fumihiro, SAKAATA Sei-ichiro, The Computational Mechanics Conference, 2009 10 10
- 2104 Convex-Path-based K-CSSL method for Approximate Global Optimization, TANAKA Hiroyoshi, SAKATA Sei-ichiro, ASHIDA Fumihiro, The Computational Mechanics Conference, 2009 10 10
- OS0419 First Order Perturbation-based Stochastic Homogenization Analysis for Short Fiber Reinforced Composite Materials, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2009 07 24 Summary:This paper describes stochastic homogenization analysis of a short-fiber reinforced composite material with using the first-order perturbation-based stochastic homogenization method. In this paper, the fibers are aligned unidirectionally, and a geometrical variable is only length of the short fiber. Using the perturbation-based technique, influence of the length of the short fiber on the stochastic property of a homogenized elastic property of a short fiber reinforced composite material is investigated. At first, from comparison between the perturbation-based approach and the Monte-Carlo simulation, validity of the perturbation-based approach is investigated. Next, with the numerical results, a relationship between the stochastic characteristics and the length of the fiber are illustrated.
- OS0418 Stochastic Analysis of Microscopic Stress in Fiber Reinforced Composites Considering Uncertainty in a Microscopic Elastic Property, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2009 07 24 Summary:This paper describes a numerical result of stochastic analysis on a random variation of microscopic stress caused by a random variation in a material property of component materials. The stochastic properties such as the expectation, variance or coefficient of variance are computed with the Monte-Carlo simulation. The microscopic stress is analyzed with using the homogenization theory based finite element analysis. As an example, a microscopic stress in a unidirectional fiber reinforced composite under a uni-axial macroscopic strain is taken into account. The macroscopic strain may change caused by a random variation in a material property of a component material, the stochastic characteristic of the microscopic stress under both constant strain and stress conditions are investigated. From numerical results, it is confirmed that the stochastic characteristics of the microscopic stress depend on both a kind of microscopic random variation and macroscopic condition on the strain field.
- OS0119 Analysis on Influence of Variation in Volume Fraction of Fiber on Stochastic Property of Homogenized Elastic Property of Fiber Reinforced Composite Material, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2009 07 24 Summary:This paper discusses influence of variation in volume fraction of fiber on a stochastic property of a homogenized elastic property of a fiber reinforced composite material caused by a random variation in a material property or geometty of component materials. The influence is analyzed with the perturbation-based analysis using the equivalent inclusion method. With numerical results, influence of volume fraction variation on the stochastic property is discussed. Also, a limit of random variation of volume fraction of fiber in order to control a random variation of a homogenized elastic property of a composite to be less than random variation of elastic properties of component materials is investigated.
- Dynamic Thermoelastic Problems of Thin Films with Damping, Thermal Stresses 2009, 2009 06 , Thermal Stresses 2009
- Kriging-based Approximate Global Optimization using Convex-Clustering Approach, WCSMO8, 2009 06 , WCSMO8
- Optimum Design of a Piezo-Composite Disk for Control of Thermal Stress, Themal Stresses 2009, 2009 06 , Themal Stresses 2009
- Microstructural optimization for minimizing stochastic variation of a homogenized elastic property of composites using stochastic homogenization analysis, 2009 03 10
- One-Dimensional Generalized Thermoelastic Analysis of a Nonlinear Piezoelectric Thin Film with Damping, ACMFMS2008, 2008 10 , ACMFMS2008
- Design of a Smart Composite Disk for Control of Thermal Stresses, ACMFMS2008, 2008 10 , ACMFMS2008
- Control of Transient Thermal Stress in a Two-Layered Piezoelectric Composite Disk, ACMFMS2008, 2008 10 , ACMFMS2008
- Shape Optimization of a Graded Structure Considering a Contact Problem using DFP-Based Neural Network, ACMFMS2008, 2008 10 , ACMFMS2008
- One-Dimensional Generalized Thermoelastic Analysis of a Composite Thin Film with Damping, ACMFMS2008, 2008 10 , ACMFMS2008
- Inverse Thermoelastic Problem of a Radially-Polarized Piezoceramic Hollow Cylinder, ACMFMS2008, 2008 10 , ACMFMS2008
- On Kriging Approximation for Optimization of Laminated Composites, ACMFMS2008, 2008 10 , ACMFMS2008
- Comparative Study on Stochastic Analysis with the Perturbation based Homogeniaztion and Equivalent Inclusion Method considering Microscopic Uncertainty of Material Property, ACMFMS2008, 2008 10 , ACMFMS2008
- Stochastic Homogenization Analsysi of Fiber Reinforced Composites Considering Three-Dimensional Geometrial Random Variation of Fiber, ACMFMS2008, 2008 10 , ACMFMS2008
- One-Dimensional Generalized Thermoelastic Analysis of a Thin Film using Green-Naghdi Therory, ACMFMS2008, 2008 10 , ACMFMS2008
- On Local Stress Analysis in Multi-scale Problem for Inhomogeneous Materials, ACMFMS2008, 2008 10 , ACMFMS2008
- Microstructural Optimization of Fiber Reinforced Composites considering a Stochastic Homogenization Problem, ACMFMS2008, 2008 10 , ACMFMS2008
- OS1420 First Order Perturbation Based Stochastic Homogenization Analysis of Fiber Reinforced Composites using Equivalent Inclusion Method, SAKATA Sei-ichiro, ASHIDA Fumihiro, Kojima Tomoyuki, 2008 09 16
- OS1406 Linear Optimum Control of Thermal Stress in a Piezoelectric Composite Disk, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2008 09 16
- 3304 Structural Optimization with using the Kriging-Polynomial Hybrid Approximation, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2008 08 02 Summary:This paper discusses a new approach for constructing an approximated surface of an unknown response surface. The proposed hybrid algorithm consists of two processes: (1) global approximation with Kriging method, (2) local approximation with polynomial approximation. One of the key ideas of the proposed method is Hessian evaluation of an estimated surface, which can be estimated using the Kriging-based formulation, for accurate approximation based on a quadratic polynomial approximation. In order to investigate validity and effectiveness of the proposed method, it is applied to a layout optimization problem of a beam structure. Compared to the result of an optimality-based approach, effectiveness of the proposed method is illustrated.
- Optimum control of thermal stress in a Piezo-composite disk, ICTAM2008, 2008 08 , ICTAM2008
- Topology Optimization of Continuum by Succesive Approximate Optimization, ICTAM2008, 2008 08 , ICTAM2008
- 203 One-Dimensional Generalized Thermoelastic Analysis of a Functionally Graded Piezoelectric Thin Film with Damping, MORIWAKI Takafumi, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2008 02 26
- On Stochastic Analysis using Higher-order Perturbation Theory for Homogenization Problem of Composite Mateirals, APCOM 07, 2007 12 , APCOM 07
- P013 Analysis of a Smart Composite Disk Controlling Maximum Thermal Stress : Constrained Optimization Problem, KONDO Kenta, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2007 10 24 Summary:This paper discuss a stress control problem in a three-layered composite disk consisting of a transversely isotropic structural layer onto which piezoelectric sensor and actuator layers of crystal 6mm are perfectly bounded. It is considered that some electrodes are arranged concentrically on the upper surface of the actuator layer. When an unknown heating temperature distribution acts on the bottom surface of the disk, the electric potential distribution is assumed to be measured on the upper surface of the sensor layer. Then, the maximum thermal stress induced in the structural layer can be controlled by applying an appropriate voltage to each electrode. The voltages applied to electrodes are determined by optimization so that the maximum thermal stress in the structural layer is minimized subject to constrains on the stresses in the piezoelectric layers. Finally, numerical results are shown in tables.
- 430 Stochastic Response Analysis of FRP using Second-order Perturbation-based Homogenization Method, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, 2007 10 24 Summary:This paper discusses a stochastic response analysis using the second-order perturbation-based homogenization method for fiber reinforced composites. The perturbation method is used for estimating stochastic characteristics such as the expectation or variance of a homogenized elastic tensor or a homogenized equivalent elastic constant of FRP. Those stochastic characteristics will be estimated using the first-order perturbation based homogenization method in case of linear stochastic response of a homogenized elastic property however, a stochastic response in some other problems considering non-linearity or large stochastic variation cannot be estimated accurately using the first-order perturbation method. In this paper, therefore, the second-order perturbation-based homogenization method is used for the estimation. At first, an outline of the second-order perturbation-based homogenization method is introduced. Also, the perturbation-based procedure for computing a perturbation term of a homogenized equivalent elastic constant is introduced. Those methods are applied to a stochastic analysis for a homogenization problem of FRP. From the numerical results, effectiveness and a problem of the second-order perturbation method are illustrated.
- 2206 Stochastic Variation of Equivalent Elastic Property of GFRP caused by Dispersion in Elastic Constants of Component material : influence of geometrical configuration of microstructure, Kojima Tomoyuki, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2007 09 07 Summary:This paper discusses influence of microscopic uncertainty of material property on homogenized macroscopic properties of unidirectional GFRP. Especially, influence of microscopic geometrical configuration such as a cross sectional shape of fiber or volume fraction of fiber on expectation and variation of the homogenized elastic property is taken into account. The influence is investigated using the homogenization method based finite element analysis and Monte-Carlo simulation. The numerical results illustrate influence of a microscopic geometric configuration on the stochastic characteristic of the homogenized property.
- 2204 Stochastic Response Analysis of Fiber Reinforced Composites using First-order Perturbation based Homogenization Method, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, 2007 09 07 Summary:This paper discusses a three-dimensional stochastic response analysis for a homogenization problem of fiber reinforced composites using the first-order perturbation method and the homogenization method. In addition to the homogenized elastic tensor, stochastic characteristics of homogenized elastic constants are investigated using the first-order perturbation method. Assuming an orthotropic material, a homogenized elastic constant is computed from a homogenized compliance matrix. Uncertainty of microscopic material property is taken into account in this paper. As a numerical example, stochastic characteristics of homogenized elastic tensor for a unidirectional fiber reinforced composites, which has periodic microstructure with hexagonal arrangement, is investigated. From the numerical results, effectiveness and limitation of the first-order perturbation method is illustrated
- 2216 Displacement control of Piezoelectric Composite Disk using DFP-based Neural Network : stabilization of training, TSUBOKURA Takahiro, SAKATA Sei-ichiro, ASHIDA Fumihiro, 2007 09 07 Summary:This paper discusses an effect of stabilization of learning process for DFP-based hierarchical neural network on a result of approximate optimization for controlling deformation of a piezoelectric composite disk. Though the DFP formula enables to enhance a learning speed of the neural network, a learning result of the DFP-based neural network is heavily dependent on a set of initial value for weighing coefficients. This will cause a fatal problem in the use of approximate optimization. The proposed stabilization algorithm is applied to the neural network-based approximate optimization technique. From the numerical result, it is shown that the proposed stabilization algorithm improves accuracy of an approximated optimum result using the DFP-based neural network.
- Optimum Design of a Piezo- Composite Disk for Control of Thermoelastic Displacement Distribution, Thermal Stresses 2007, 2007 06 , Thermal Stresses 2007
- On Sampling Strategy for Kriging-Polynomial Hybrid Approximate Optimization, The 7th WCSMO, 2007 05 , The 7th WCSMO
- 106 Kriging-based Approximate Optimization using Dispersed Sampling Data, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, The Computational Mechanics Conference, 2006 11 02
- 3658 Accuracy of Gradient and Hessian Estimation in Approximate Optimization, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, 2006 09 15 Summary:This paper discusses accuracy of estimated gradient and Hessian components in approximate optimization. Several flexible approximate optimization methods can estimate gradient and Hessian components of an estimated surface without using finite difference, and it will be available in approximate optimization process using a gradient-based optimization method. Since its accuracy affects an estimated result of optimum solution or convexity, accuracy of estimations by those flexible methods should be investigated. In this study, accuracy of gradient and Hessian estimation by Kriging method is investigated. At first, in this paper, a formulation for gradient and Hessian estimations by Kriging method is described. Next, accuracy of those estimations is discussed with numerical results.
- 3656 Control of Thermal Stress in a Piezoelectric Composite Disk by a Stepwise Applied Electric Potential Distribution : Optimum Design of Electrode Dimensions, MATSUMOTO Kouhei, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2006 09 15 Summary:This paper discusses a stress control problem in a layered composite disk consisting of a transversely isotropic structural layer onto which a number of piezoelectric layers of crystal class 6mm are perfectly bonded. It is considered that some electrodes are arranged concentrically on the upper surface of each piezoelectric layer. When an axisymmetric heating temperature acts on the bottom free surface, the maximum thermal stress induced in the structural layer is controlled by applying an appropriate voltage to each electrode. The voltages applied to electrodes are determined by optimization using the BFGS quasi-Newton method so that the maximum thermal stress in the structural layer is minimized subject to constraints on the stresses in the piezoelectric layers. Finally, numerical results obtained for a composite disk consisting of a transversely isotropic CFRP layer and a number of cadmium selenide layers of crystal class 6mm are shown in tables.
- 3640 One Dimensional Generalized Thermoelastic Analysis of Nonlinear Elastic Solids with damping, MAEDA Mayuko, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2006 09 15 Summary:This paper deals with the one-dimensional generalized thermoelasticity in a homogeneous isotropic infinite thin plate exhibiting an inelastic behavior, when a damping effect is taken into account. The plate is initially at zero temperature and subjected to a ramp heating on the top surface. The governing equations for the temperature change, heat flux, particle velocity and axial stress are expressed by a set of first-order partial differential equations. This system of equations has been numerically analyzed by employing the method of characteristics. Finally, the effects of the damping coefficient on time histories of the axial stress and temperature change are illustrated graphically.
- P15 Avoiding Overfitting with Referring to Gradient Information for DFP-Based Hierarchical Neural Network, KAWAGUCHI Takahisa, ASHIDA Fumihiro, SAKATA Sei-ichiro, Proceedings of the ... annual meeting of JSME/MMD, 2006 08 03
- P13 An Efficient Approach to Control Transient Deformation in a Two-layer Piezoelectric Composite Circular Disk, TAKENAKA Sho, ASHIDA Fumihiro, SAKATA Sei-ichiro, Proceedings of the ... annual meeting of JSME/MMD, 2006 08 03
- 107 Convexity Estimation of Design Surface in Approximate Structural Optimization, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, Proceedings of the ... annual meeting of JSME/MMD, 2006 08 03
- Kriging-based Estimation with Noisy Data, ECCM2006, 2006 06 , ECCM2006
- Control of Thermal Stress in a Piezoelectric Composite Disk by a Stepwise Applied Electric Potential Distribution, ECCM2006, 2006 06 , ECCM2006
- 118 Control of Thermal Stress in a Piezoelectric Composite Disk by a Stepwise Applied Electric Potential Distribution, MATSUMOTO Kouhei, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2006 02 23
- 117 One Dimensional Generalized Thermoelastic Analysis of a Composite Plate, MAEDA Mayuko, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2006 02 23
- 106 On Approximate Optimization method for Microstructural Optimization of Fiber Reinforced Composites, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, Proceedings of the ... annual meeting of JSME/MMD, 2005 11 03
- 105 Effect of the Normalization Range of Training Data on Neural Network Approximation for Microstructural Optimization of FRP, KAWAGUCHI Takahisa, SAKATA Seiichiro, ASHIDA Fumihiro, Proceedings of the ... annual meeting of JSME/MMD, 2005 11 03
- Comparative Study on Gradient and Hessian Estimation by Kriging and Neural Network for Optimization, ICCMSE 2005, 2005 11 , ICCMSE 2005
- 1413 Effect of a Design Procedure on Simultaneous Shape and Material Composition Optimization of a Two-Dimensional Rectangular Structure, SAKATA Sei-ichiro, ASHIDA Fumihiro, ZAKO Masaru, 2005 09 18 Summary:This paper describes an effect of a design procedure on optimizing results of simultaneous shape and material composition optimization of two-dimensional rectangular structure. Material is composed of epoxy and air, macroscopic material properties are determined by those composition. Shape of a structure is determined by coordinates of its surface. Optimality criteria method based on Lagrange multiplier method is applied to optimization. Numerical results illustrate differences of optimizing results by different optimizing procedure, and a proper procedure such as alternative design of shape and material composition at each optimization step is effective to improve an optimizing result.
- 1418 Control of Thermoelastic Displacement in a Two-Layered Composite Disk by Applying Stepwise Electric Potentials, ASHIDA Fumihiro, SAKATA Sei-ichiro, YOSHIDA Shinji, 2005 09 18 Summary:This paper discusses a displacement control problem in a two-layered composite disk consisting of a transversely isotropic structural layer onto which a piezoceramic layer of crystal class 6mm is perfectly bonded. It is considered that some electrodes are concentrically arranged on the top surface of the disk. When an axisymmetric heating temperature acts on the bottom surface of the disk, the thermally induced displacement distribution on the bottom surface is controlled by applying a stepwise applied electric potential distribution to the top surface. The voltage which could be applied to each electrode is determined by optimization so that the displacement over the bottom surface of the disk has a desired distribution.
- Control of Thermoelastic Displacement in a Layered Piezoelectric Composite Disk by a Stepwise Applied Electric Potentials Distribution, Thermal Stresses 2005, 2005 05 , Thermal Stresses 2005
- Piezoelectric Control of Temperature-induced Plate Vibrations, Thermal Stresses 2005, 2005 05 , Thermal Stresses 2005
- 703 Control of Thermally Induced Vibration of a Beam by Taking Damping into Account, TAKAHASHI Yoshiki, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2005 02 24
- Determination of a Stepwise Electric Potential Controlling a Thermoelastic Displacement in a Layered Composite Plate, YOSHIDA Shinji, ASHIDA Fumihiro, SAKATA Sei-ichiro, The Computational Mechanics Conference, 2004 11 17
- Inverse Transient Thermoelastic Problem of a Piezoceramic Hollow Cylinder Subjected to Asymmetric Surface Heating, ASHIDA Fumihiro, SAKATA Sei-ichiro, NAKATA Hiroyuki, 2004 09 04 Summary:This paper deals with an inverse problem of transient thermoelasticity in a piezoceramic hollow cylinder of crystal class 6mm. It is assumed that the cylinder is poled in the radial direction. An unknown asymmetric heating temperature on the inner surface is inferred from the knowledge of the electric potential thermally induced on the outer surface. The finite difference formulation with respect to a time variable is employed, so that this inverse problem can be solved. Numerical calculations have been carried out for a hollow cylinder of cadmium selenide. Numerical results for the inferred heating temperature are shown in a figure.
- Control of Thermaly Induced Vibration of a Beam : In case of Piezoelectric and Host Layers with Different Thermal Diffusivities, TAKAHASHI Yoshiki, ASHIDA Fumihiro, SAKATA Sei-ichiro, 2004 03 06
- Improvement in Computational Efficiency of Structural Optimization Using Kriging Method, SAKATA Seiichiro, ASHIDA Fumihiro, ZAKO Masaru, The Computational Mechanics Conference, 2003 11 22
- Control of Transient Thermoelastic Displacement in an Intelligent Three-Layered Composite Disk, Ashida Fumihiro, Sakata Seiichiro, Yamashita Yuji, The Computational Mechanics Conference, 2003 11 22
- Homogenization Analysis of Hollow Fiber Composites To Emerge a Thermal Function, SAKATA Seiichiro, ASHIDA Fumihiro, ZAKO Masaru, Proceedings of the ... annual meeting of JSME/MMD, 2003 09 23 Summary:This paper describes a homogenization analysis of hollow fiber composite material. Generally a porous material has low thermal conductivity, but it is difficult to control both thermal and mechanical property because of difficulty on control of shape and location of holes in composite media. In this study, a homogenization analysis and transient heat conductivity analysis of a hollow fiber composite plate is carried out. Effect of microstructural design of hollow fiber on homogenized thermal and mechanical properties are also investigated. Numerical results illustrate validity of the analysis and necessity of the microstructural design of hollow fiber composite material.
- Determination of a Stepwise Electric Potential Controlling a Thermoelastic Displacement in a Two-layered Composite Plate, YOSHIDA Shinji, ASHIDA Fumihiro, SAKATA Seiichiro, Proceedings of the ... annual meeting of JSME/MMD, 2003 09 23 Summary:This paper discusses a displacement control problem in a two-layered composite plate consisting of a transversely isotropic structural layer onto which a piezoceramic layer of crystal class 6mm is perfectly bonded. It is considered that some electrodes are metallized on the top free surface in a concentric configuration. When an axisymmetric heating temperature acts on the bottom free surface, the thermally induced elastic displacement on the structural layer surface could be controlled by applying a different electric voltage to each electrode. The applied electric potentials are determined by an approximate optimization using neural networks so that the difference between the desired and thermally induced elastic displacement distributions is minimized. Finally, numerical results for the controlled displacement distribution and applied electric potentials are illustrated graphically.
- Microstructural Optimization of Composite Plate for Improvement of its Reliability Using Spatial Approximation, SAKATA Seiichiro, ASHIDA Fumihiro, ZAKO Masaru, 2003 08 05 Summary:This paper describes a microscopic optimization of fiber reinforced plastics to improve a reliability of a composite structure. To improve a reliability, minimum residual elasticity in a composite plate after loading is maximized. A microstructure is modeled by using the Fixed Grid Method, Macroscopic properties are calculated by using the Homogenization method. A microstucture is optimized by using the Kriging approximation and a gradient-based optimization method. As an example, a microstrcture of a composite plate under bending and compression is optimized by using the proposed method. The numerical result illustrates an effectiveness of the proposed method.
- Thermoelastic Problem of a Piezoceramic Circular Plate with a Relaxation Time, Ashida Fumihiro, Sakata Seiichiro, Uchida Kazumasa, 2003 08 05 Summary:The present paper deals with a thermoelastic problem of a piezoceramic circular plate of crystal class 6mm symmetry, when a relaxation time is taken into account in the temperature field. One boundary surface of the plate is exposed to an ambient temperature distribution, whereas the other boundary surface is kept at the initial temperature. An exact solution to the temperature field is obtained by means of the Laplace transform technique. The elastic and electric fields are analyzed by employing the piezothermoelastic potential function method. Numerical calculations have been carried out for a cadmium selenide plate, and numerical results are illustrated graphically.
- Optimization of Beam Structure for Transient Heat Conductivity Using Kriging Approximation, Thernal Stresses 2003, 2003 06 , Thernal Stresses 2003
- Optimum Design of a Multi-Layered Composite Plate Using Neural Networks, Thernal Stresses 2003, 2003 06 , Thernal Stresses 2003
- Optimum Design of a Multi-layered Piezoceramic Plate by Neural Network, HORINOKUCHI Naokazu, ASHIDA Fumihiro, SAKATA Seiichiro, Proceedings of the ... annual meeting of JSME/MMD, 2002 10 10 Summary:This paper deals with optimization of the layer thicknesses of a multi-layered piezoceramic plate by employing the neural network approximation. Electric potentials controlling a thermally induced elastic displacement of the plate are minimized subject to stress constraints. A learning cost is considered to be high in the case of this problem. By introducing the quasi-Newton method as an updating formula for connection weights, a learning algorithm is improved and the cost of the neural network approximation is greatly saved. Numerical results have been obtained and the validity of the proposed method is demonstrated.
- Microscopic Structural Optimization of FRP Using Spatial Estimation, SAKATA Seiichiro, ASHIDA Fumihiro, ZAKO Masaru, 2002 09 20 Summary:This paper describes a microscopic structural optimization of fiber reinforced plastics using spatial estimation and a gradient optimization method. A residual component of a homogenized elastic tensor after microscopic fracture is maximized. Fixed grid model is used as microscopic FRP model. Homogenization method is used in order to calculate a macroscopic homogenized elastic tensor. A solution space is estimated using the Kriging method. The Grauss type semivariogram model is adopted in this paper. Gradient method is suitable to solve the optimization problem, which is estimated using the Kriging method, because gradient components on an estimated surface can be obtained without using a finite differential. In this paper, CSSL method is used as an optimizer. Using the proposed method, an estimated optimum solution to maximize the residual rigidity of GFRP is obtained, a validity and effectiveness of the method is confirmed.
- Dynamic Thermoelastic Problem of a Piezoceramic Plate with a Relaxation Time, Ashida Fumihiro, Sakata Seiichiro, 2002 09 20 Summary:The present paper deals with the dynamic thermoelastic problem of a thin piezoelectric plate of crystal class 6mm, when not only a relaxation time in the temperature field but also an inertial effect in the elastic field is taken into account. One boundary surface of the thin plate is exposed to a uniform ambient temperature, whereas the other boundary surface is kept at the initial temperature. An exact solution to this problem is obtained by employing the Laplace transform technique. Numerical calculations have been carried out for a thin PZT-5A plate, and the numerical results are illustrated graphically.
- Structural Optimization Using Spatial Estimation and Gradient Method, SAKATA Seiichiro, ASHIDA Fumihiro, ZAKO Masaru, M&M Lakeside Summer Symposium, 2002 08 06 Summary:This paper describes about a new structural optimization method by using spatial estimation. The proposed method consists of two main processes. One is a space estimation process by Kriging method, and the other is an optimization process by a gradient method. An estimated solution space can be generated without an assumption on an order of approximated function. Kriging method requires an assumption on semivariogram model. In this paper, Gauss model is assumed. Nonlinear programming is used as a local optimizer in the proposed design system, and it is available to use because a gradient component on an estimated surface can be obtained analytically. Some numerical examples are illustrated in order to evaluate a validity and effectiveness of the proposed method.
- 104 Analysis of Transient Plane Thermal Stress in a Piezoceramic Circular Plate of Crystal Class 6mm, Ashida Fumihiro, Sakata Seiichiro, Takatsuka Kouji, 2001 09 21
- K-0613 Control of Transient Thermoelastic Displacement in a Two-Layer Composite Disk Consisting of Transversely Isotropic and Piezoceramic Layers, YAMASHITA Yuji, ASHIDA Fumihiro, SAKATA Seiichiro, 2001 08 22 Summary:Control of elastic displacement in a two-layer composite circular disk subjected to axisymmetric heating is investigated. The disk consists of a transversely isotropic structural layer onto which a piezoceramic layer of crystal class 6mm is bonded. First, a solution procedure based upon potential functions is used to analyze the elastic and electric fields in the disk, when a transient ambient temperature acts on the free surface of the structural layer. Then a distribution of transient electric potential applied to the piezoceramic layer is determined, such that the resultant elastic displacement on the free surface of the structural layer has the desired distribution. Numerical results for the applied electric potential and elastic displacement are illustrated graphically.
- K-0611 An Examination on the Design Variables and the Design Procedures for the Microstructural Design of the Composite Material, HORINOKUCHI Naokazu, SAKATA Seiishiro, ASHIDA Fumihiro, 2001 08 22 Summary:We present about an examination on the design method to optimize some kind variables. It is considered that microstructural design of composite material by using beam model. In the case that additional reinforcements are inserted to a base structure, topology, location or cross-sectional shape of reinforcements will be considered as design variables. In order to construct a design system for simultaneous design of both layout and cross-sectional size, differences of each solution which can be obtained by different design procedures for the multiple types of design variables are investigated. In this time, a cantilever with a slit at the center is optimized by using the steepest descent method as one of the simplest example. The results show a difficulty of the design and a necessity of the design method which can search the optimum solution stably with lower computational cost.
- Analysis of Plane Thermal Stress Problem in a Piezoceramic Circular Plate of Crystal Class 6mm (Traction-Free Edge Condition), Ashida Fumihiro, Sakata Seiichiro, The Computational Mechanics Conference, 2000 11 27
- Structural Optimization of Reinforcement for Thermal Deformation, SAKATA Seiichiro, ASHIDA Fumihiro, ZAKO Masaru, The Computational Mechanics Conference, 2000 11 27
- Effect of Crack Properties on Evaluation of Accumulative Traffic Loads Measured by Sacrificial Test Pieces, Mukai Shingo, Sakino Yoshihiro, Sakata Seiichiro, Horikawa Kohsuke, Pre-Prints of the National Meeting of JWS, 2000 09 05