Simplified Estimation of Inelastic Behavior in Local Section of Components Subjected to Membrane, Bending and Peak Stresses Using Stress Redistribution Locus Method

Abstract

Stress redistribution locus (SRL) method has been proposed to estimate stress and strain behaviors at the specific point employing the elastic Finite Element Analysis, an inelastic constitutive equation, and a unique hyperbolic curve: ε= {1/σ + (κ - 1) σ}/κ , where ε and σ show dimensionless equivalent strain and stress that are normalized by the elastic FEA result. FE analyses incorporating plasticity and creep in were performed for plates with a single edge notch where membrane, bending, and peak stresses appeared at the same time. The normalized equivalent stress and strain behavior was compared with the proposed SRL curve. Both at smaller deformation under monotonic loadings and at the early time under creep, the normalized equivalent stress and strain state was depicted on the SRL curve of κ=1.6 in the case of the plane stress condition. With the larger deformation and as time went by, the stress and strain locus went away from the SRL curve of κ=1.6, and approached to the one of κ=1.0. However the inelastic behavior almost followed the SRL curve of κ=1.6 in the generalized plane strain condition. Whenever the inelastic zone in the local section was limited, the precise inelastic behavior would be described using the proposed SRL curve of κ=1.6.