Search

The traditional perturbation-based stochastic finite element method has the inherent limitation of requiring small uncertainties to ensure reliable results. To overcome this limitation, this paper presents a new method that redefines the stochastic problem into some sub-domains of random variables. Then, the stochastic structural responses defined in the global domain can be explicitly reconstructed from the responses obtained in each sub-domain. In this way, the uncertainties of random variables could be relatively large to achieve the acceptable accuracy. In addition, this method is also able to deal with stochastic problems with repeated eigenvalues. Numerical examples are presented to illustrate the validity and capability of this new method by comparing the results with ones from Monte Carlo simulations. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Large-scale space structures may experience unexpected thermal-elastic deformation due to thermal loadings in space. This thermal response could be minimized by using optimization method in design phase and the uncertainty of material properties should also be considered to ensure the reliable performance of the produced structure. For this purpose, the robust optimization is applied to this kind of structures in this paper. Firstly, a perturbation based stochastic finite element program is developed, which is tailored for the problem of thermal-elastic deformation of thin-walled structures subjected to incident thermal flux and energy emission through radiation. Based on this program, a robust design scheme is formulated as a two-objective optimization problem, in which all required sensitivities are calculated analytically. Then, the Pareto front of this problem is effectively determined by using the adaptive weighted sum method. Finally, numerical examples are presented to illustrate the validity and capability of this proposed method. [ABSTRACT FROM AUTHOR]