Characterization of random stress fields obtained from polycrystalline aggregate calculations using multi-scale stochastic finite elements

Authors

Sudret, B., Dang, H. X., Berveiller, M., Zeghadi, A. and Yalamas, T.

Abstract

The spatial variability of stress fields resulting from polycrystalline aggregate calculations involving random grain geometry and crystal orientations is investigated. A periodogram-based method is proposed to identify the properties of homogeneous Gaussian random fields (power spectral density and related covariance structure). Based on a set of finite element polycrystalline aggregate calculations the properties of the maximal principal stress field are identified. Two cases are considered, using either a fixed or random grain geometry. The stability of the method w.r.t the number of samples and the load level (up to 3.5 % macroscopic deformation) is investigated.