Dual-horizon bond-based peridynamic model for monotonic ductile fracture with PDDO-based elastoplastic correction

This study presents a dual-horizon bond-based peridynamic (BB-PD) model for monotonic ductile fracture analysis with a Peridynamic Differential Operator (PDDO)-based elastoplastic correction strategy. The proposed framework aims to retain the simplicity of BB-PD while improving its capability to represent localized plastic deformation, progressive damage evolution, and nonuniform particle discretizations. In the formulation, the PDDO is employed to evaluate strain and stress fields in locally refined and irregular particle arrangements. The elastically computed local stress fields are then mapped to elastoplastic stress–strain responses through Neuber’s rule combined with the Ramberg-Osgood relation. To avoid the abrupt brittle-like response associated with sudden bond deletion, a gradual stress-softening damage model is introduced, in which bond interactions progressively degrade as the local damage variable evolves. The dual-horizon formulation enables fine discretization around crack tips, notch regions, and stress concentration zones while retaining a coarser discretization elsewhere, thereby improving computational efficiency without ghost-force-related inconsistencies. The performance of the proposed model is assessed through ductile fracture examples involving pre-cracked and notched plate geometries under monotonic tensile loading. The results demonstrate that the proposed framework can capture crack propagation, plastic strain localization, and force-displacement responses in good agreement with reference results.