Combined experimental/theoretical approach to residual stresses within multiplicative elasto-plasticity

TL;DR

This paper introduces a combined experimental and theoretical approach for modeling and assessing residual stresses in viscoplastic structures using multiplicative elasto-plasticity, with applications to welded plates.

Contribution

It develops an efficient modeling framework for residual stresses based on reference configuration transitions and extends numerical algorithms to pre-stressed materials.

Findings

Successful simulation of residual stress fields in welded plates

Demonstration of residual stress reduction through mechanical treatment

Novel combined experimental/theoretical residual stress assessment method

Abstract

The study is devoted to geometrically non-linear modelling of viscoplastic structures with residual stresses. We advocate and develop a special approach to residual stresses based on the transition between reference configurations. The finite strain kinematics of the viscoplastic material is modelled by the multiplicative decomposition of the deformation gradient tensor. Numerical algorithms originally developed for unstressed materials are extended to materials with pre-stresses. Owing to the weak invariance of constitutive equations, the incorporation of pre-stresses happens without additional costs. Thus, the advocated approach is especially efficient. A novel experimental/theoretical method for assessment of residual stresses in welded structures is presented; the method combines advantages of purely experimental and theoretical approaches. To demonstrate the applicability of the proposed procedure, we simulate plate welding. As an example we show that the procedure allows to extrapolate the filed of residual stresses away from the measurement points. As another example, we address the reduction of weldment-related residual stresses by mechanical treatment.