Prediction of micro-crack initiation in high strength steels using Weibull distribution

The presented paper deals with the computational analyses of crack initiation period in laser cut mechanical elements using improved Tanaka–Mura model. In the proposed computational model, the material microstructure is modelled with Voronoi tessellation where crystal grains are represented with a random oriented cell structure. The proposed model is used to determine the crack initiation life in laser cut area of tensile loaded test specimen made of high strength steel with martensitic microstructure. In the presented study, several computational analyses have been done on each stress level, where different grain orientations generated with Voronoi tessellation are considered in each simulation. Because of different grain orientations different crack initiation life’s are obtained on the same stress level. The computational results are then subjected to the statistical analyses using Weibull distribution.

► Improvement of the Tanaka–Mura crack nucleation model.
► An algorithm for generation of synthetic microstructure using Voronoi tessellation.
► An algorithm for simulation of fatigue crack initiation in steels with martensitic microstructure.
► Statistical aspect of the fatigue crack initiation period.