LARGE DEFORMATION AND FRACTURE ANALYSIS OF THIN PLATE BENDING BASED ON PERIDYNAMICS

Thin plate structures are widely used in the fields of automobiles, ships, and aerospace because of their excellent load-bearing performance, light weight and easy processing. However, in practical applications, thin plate structures often produce large displacement, rotation and even cause crack initiation and growth under small loads, and then the overall structure fractures. Therefore, it is of great engineering practical significance to establish a crack growth and fracture simulation model of thin plate structures in the process of large deformation. In this paper, a peridynamic (PD) and classical continuum mechanics (CCM) coupling model for geometrically nonlinear deformation and fracture analysis of thin plate structures is established. First of all, the updated Lagrangian formula is used to obtain the expression of virtual strain energy density increment of thin plates at each increment step in large deformation analysis under von Karman's hypothesis. Then, the PD constitutive parameters of geometrically nonlinear micro-beam bond are obtained by using the virtual work principle and homogenization hypothesis. After that, the virtual strain energy density increments of the PD model and CCM model for geometrically large deformation thin plate were respectively established, and the geometrically large deformation PD-CCM coupling model of the thin plate was established. Finally, the progressive fracture process of the thin plate structure under the action of lateral deformation is simulated, and the simulation results are highly consistent with the experimental results, which verifies the accuracy of the proposed geometrically nonlinear PD-CCM coupling model. It is shown that the proposed geometrically nonlinear PD-CCM coupling model is simple and efficient without restriction on material parameters and consideration of boundary effects, and can be well used to predict local damage and structural fracture of thin plate structures during geometrically large deformations. It is beneficial to the fracture safety evaluation and theoretical development of thin plate structures.