An elastoplastic peridynamic beam model for large bending deformation and fracture analysis

Abstract

The present study establishes an elastoplastic peridynamic (PD) beam model, which effectively incorporates the development of plasticity across both the cross-section and length of the beam, aiming to accurately capture the large bending deformation and fracture of metal frame structures. Firstly, the equivalent plastic modulus is derived to describe the plastic development of the beam cross-section, and then the expression of the incremental strain energy density of the beam in a large bending deformation elastoplastic process can be derived based on the classical continuum mechanics (CCM) theory. Secondly, the equivalent plastic micromoduli of the micro-beam bond are obtained from the incremental strain energy density of the beam in a large bending deformation elastoplastic process using the homogenization principle. Thirdly, the yield condition of the micro-beam bond is derived to determine its elastoplastic stage, and the elastoplastic PD-CCM coupling beam model is established via the morphing method to improve computational efficiency. Finally, the effectiveness and accuracy of the proposed elastoplastic PD-CCM beam model are verified by several numerical examples.