Finite Element Modelling of a Series of Austenitic Stainless Steel 316 L Weldments to Inform Thermoelastic Stress Analysis Residual Stress Assessment

Abstract

The RESIST (Residual Stress and Structural Integrity Studies using Thermography) project aims to develop a non-contact, non-destructive, full-field measurement and portable residual stress assessment technique based on thermoelastic stress analysis (TSA). The TSA residual stress assessment (RSA) technique relies upon a change in the thermal expansion coefficient when a material is subjected to plastic straining. TSA RSA has been successfully applied to non-welded materials, so the next stage is to assess the feasibility of application on weldments. The study focuses on establishing the validation of the technique on austenitic stainless steel AISI 316 L (EN 1.4404), which is commonly used in power generation industry. A series of increasingly complex ‘weld mock-ups’ made out of 316 L are designed to test the TSA RSA approach. Finite element (FE) simulations of the welded mock-ups were produced. The design, FE modelling and manufacture of two of the mock-ups are presented. The expected amount of plastic strain is compared with the TSA assessment in another part of the RESIST project, and thus, informs the validation of the technique on weldments.