Stochastic Creep Damage Estimation in Pipings with Spatial Non-gaussian Uncertainties Using Spectral Stochastic Finite Element Method

Abstract

This study focuses on the development of stochastic finite element basedmethodology for damage assessment of piping components that carry high temperature fluids. The primary damagingmechanism is assumed to be due to thermal creep. The material properties are assumed to be spatially inhomogeneous and are modeled as 2-D non-Gaussian random fields. A spectral stochastic finite element based methodology is developed where the non-Gaussian random fields are determined by using optimal linear expansion scheme (OLE). The corresponding finite element models for the structure are shown to be functions of a vector of correlated non-Gaussian random variables. Monte Carlo simulations (MCS) are carried out to estimate the 2-D non-Gaussian stress fields, which inturn lead to estimates of the creep damage field at different time instants. The developments are illustrated through a numerical example involving an axisymmetric section of a circular pipe.