Ductile fracture prediction of high tensile steel EH36 using new damage functions

Abstract

This study deals with ductile fracture prediction of a marine steel using new damage functions. The stress triaxiality and Lode angle are known to be governing parameters on the ductile fracture. Recent research has reported that loading path is also one of the important parameters. A three-dimensional fracture strain surface for EH36 steel was developed based on a series of tension/compression tests subjected to the tension, shear, shear-tension, and compression. To account for the non-proportional stress effects, the linear and non-linear damage evolution models were presented with a combination of the fracture strain surface. The material constants associated with the damage evolution were identified from calibration with the experimental data. Validation of the damage-based fracture models was conducted by comparing predicted fracture initiation with the results of structural test results. The fracture model with the non-linear damage evolution predicts slightly more improved predictions than the linear damage-based fracture model.