Numerical simulation of thermomechanical stresses during thermal fatigue tests with a view to predicting its duration

Abstract

This article focuses on the analysis of thermomechanical stresses undergone by a sample during FT tests in order to predict its service life, particularly from the angle of crack propagation. This is indeed an essential complement to metallurgical analyses for the study of steel damage by FT. We present in this article the methodology pursued for analytical and numerical calculations. The approach consisted first of all in determining the thermal stresses, then mechanical stresses, via finite element structure calculations. The numerical simulation is carried out by the Finite Element Method (FEM) under ABAQUS™ in implicit resolution, using the Thermo-Elasto-Plastic (EP) and Thermo-Elasto-Visco-Plastic EVP behavior laws. The axisymmetry of the reduced specimen "SR1" (1 mm thick, geometry of revolution) and the thermal stresses makes it possible to treat the problem in two dimensions. The calculation is therefore carried out on a quarter of the meridian section of the FT specimen. The results of the numerical simulation were then used in an analysis based on fracture mechanics in order to study the cracking kinetics under transient thermal loadings.