Microstructural modeling of ductile fracture initiation in multi-phase materials

TL;DR

This paper investigates how microstructural features influence ductile fracture initiation in multi-phase materials through numerical modeling, revealing specific phase arrangements and their relative insensitivity to certain assumptions.

Contribution

It introduces a structured numerical model to analyze the effects of grain shape, damage indicators, and stress states on fracture initiation in multi-phase materials.

Findings

Distinct phase arrangements around fracture sites identified

Hard regions in tension interrupted by soft shear regions

Key features are mildly sensitive to modeling variations

Abstract

The precise mechanisms underlying the failure of multi-phase materials may be strongly dependent on the material's microstructural morphology. Micromechanical modeling has provided much insight into this dependence, but uncertainties remain about crucial modeling assumptions. This paper assesses the influence of different grain shapes, damage indicators, and stress states using a structured numerical model. A distinct spatial arrangement of phases around fracture incidents is found, consisting of hard regions in the tensile direction interrupted by soft regions in the directions of shear. These key features are only mildly sensitive to the studied variations.