Inelastic analysis versus simplified rules for stress concentration fields under variable loading and high temperature

Abstract

Phenomenological constitutive equations that describe the inelastic behaviour of advanced 9–12%Cr heat‐resistant steels at high temperature and multi‐axial stress state are used to study stress concentration fields. The model takes into account hardening/recovery, softening and damage properties by appropriate state variables. The inelastic response of a notched plate under cyclic loading/holding/unloading sequences is analysed by the finite element method and the constitutive model. Furthermore, different simplified rules that are available for rapid assessment of stress concentration fields are applied and the results are compared with the results of inelastic structural analysis. We show that the simplified rules can provide a good estimation of several points on the stress–strain loop.

Keywords:

• Neuber's rule
• Stress concentration fields
• Inelastic material model
• Cyclic loading