Strain and stress computations in stochastic finite element methods

✍ Scribed by Debraj Ghosh; Charbel Farhat

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 382 KB
• Volume: 74
• Category: Article
• ISSN: 0029-5981
• DOI: 10.1002/nme.2206

✦ Synopsis

Abstract

This paper focuses on the computation of statistical moments of strains and stresses in a random system model where uncertainty is modeled by a stochastic finite element method based on the polynomial chaos expansion. It identifies the cases where this objective can be achieved by analytical means using the orthogonality property of the chaos polynomials and those where it requires a numerical integration technique. To this effect, the applicability and efficiency of several numerical integration schemes are considered. These include the Gauss–Hermite quadrature with the direct tensor product—also known as the Kronecker product—Smolyak's approximation of such a tensor product, Monte Carlo sampling, and the Latin Hypercube sampling method. An algorithm for reducing the dimensionality of integration under a direct tensor product is also explored for optimizing the computational cost and complexity. The convergence rate and algorithmic complexity of all of these methods are discussed and illustrated with the non‐deterministic linear stress analysis of a plate. Copyright © 2007 John Wiley & Sons, Ltd.