Research on single-layer grid structures considering joint connection failure based on MDEM

Abstract

The traditional numerical simulation method ignores the volume and stiffness of the joints in single-layer grid structures. Such a simplification is not conducive to observing the failure of joint connections. This paper proposes a novel type of numerical simulation method—the multi-scale discrete element method (MDEM) to simulate the joint connection failure of single-layer grid structures. The joint and the part of the rod that is prone to plastic failure are divided by the discrete solid element method (DSEM) as a microscopic model. The other parts of the rods are simulated by the equivalent beam element method (EBEM) as a macrocosmic model, and all elements are connected with parallel bond contact. Moreover, to ensure the cooperative work of different scale models, the spring stiffness at the interface between DSEM and EBEM is derived based on the energy equivalence principle, and the effectiveness of MDEM is verified by the impact test of single-layer grid structures. Finally, the joint connection failure of single-layer grid structures is effectively simulated by MDEM in the PFC3D software, and the error between MDEM and the finite element method (FEM) is less than 4.07%.