A novel conjugated bond linear elastic model in bond-based peridynamics for fracture problems under dynamic loads

A novel conjugated bond linear elastic model is proposed and implemented into the bond-based peridynamic (BB-PD) framework. In this model, micro-elastic PD bond energy is not only related to the normal stretch of bonds, but also related to the rotation bond angles of a pair of conjugated bonds. Therefore, micro bond energy mechanism in this study is different from that in the classical continuum mechanism or the standard BB-PD. Only one micro-elastic constant in the standard BB-PD results in the limitation of the effective Poisson's ratio for isotropic material. However, the novel conjugated bond linear elastic model incorporating two micro-elastic constants are proposed, which can overcome the limitation of Poisson's ratio in the standard BB-PD. By comparing the strain energy in the proposed model with that in the classical elastic model, the corresponding micro-macro parameter relationships can be established. In addition, energy-based bond rupture criteria are implemented in the proposed numerical model to simulate fracture problems under dynamic loads. In order to verify the ability and accuracy of the proposed numerical model to simulate fracture problems under dynamic loads, some numerical examples are investigated. The present numerical results are in good agreement with the previous experimental and numerical results.