Elastoplastic Peridynamic Analysis of Crack Growth in Defective Ductile Materials

ABSTRACT We propose a new three‐dimensional peridynamic elastoplastic (3D‐PDEP) material model for simulating fractures in ductile materials, accounting for damage and plastic defects. The new material model is applied to aluminum alloys 2024‐T351 and 6061‐T6, using their experimentally obtained stress–strain curves in peridynamics. This approach allows for the simulation of both plastic and elastic deformations, as each material bond is placed on the stress–strain curve based on the stretch value. Once the material bond exceeds the elastic limit, it permanently enters the plastic zone; if it exceeds the plastic limit, it is considered broken. We introduce a new way to represent plastic and damage defects, allowing the model to include pre‐existing flaws in the material. Plastic defects are handled by changing the elastic strain limit for each bond, while damage defects are modeled by adjusting the damage strain limit, so some bonds start out broken. The model accurately predicts the elastoplastic behavior of ductile materials, as shown by comparison with experimental results. The 3D‐PDEP model also helps explain how cup‐cone fracture modes form and explores different fracture patterns in ductile materials with various defect ratios. These results improve our understanding of how fractures develop in defective ductile materials.