XFEM investigation of a crack path in residual stresses resulting from quenching

摘要

The aim of this work is the numerical study of a crack path in a residual stress field resulting from a manufacturing process such as quenching. An XFEM technique is proposed to that end and the example illustrating the quenching of a large thick plate is considered so as to demonstrate the capability of the method proposed. Indeed, during the quenching of steels, metallurgical transformations can occur, leading to high residual stresses at room temperature. From the practical point of view, the thick plate must be sawn after quenching. But it is experimentally observed that under certain quenching conditions, the crack initiated by the sawing, suddenly propagates through the thickness of the plate and then rotates through an angle of about 90°. The numerical simulation of quenching is detailed and the results obtained under two operating conditions are given. Then the XFEM technique applied to the crack propagation in a residual stress field is presented and the cracking path obtained on the quenched plate is compared to that obtained using the FEM coupled with a remeshing technique. It is shown that the computed crack path justifies experimental observations.