On Quasi-Static and Dynamic Compressive Behaviors of Interlocked Composite Kagome Lattice Structures

The quasi-static and dynamic compressive behaviors of carbon fiber-reinforced plastic (CFRP) Kagome lattice structures subjected to quasi-static load and low-velocity impact were investigated experimentally and numerically. CFRP Kagome lattice structures were fabricated by using the interlocking method. The quasi-static compression and low-velocity impact experiments were carried out and the failure mechanisms of CFRP Kagome lattice structures were explored. A user-defined material subroutine (VUMAT) involving threedimensional Hashin criterion and progressive damage evolution was developed and implemented in the refined finite element (FE) model to model the failure of composite lattice structures. Good agreement is achieved between FE simulations and experimental results. It is shown that both in-plane stiffness and the failure mode of CFRP Kagome lattice structure are sensitive to the load directions. CFRP Kagome lattice structures subjected to quasi-static load experience elastic deformation, bending/kinking failure, rib fracture, and structure collapse sequentially. CFRP Kagome lattice structures subjected to lowvelocity impact suffer from the multiple fractures at the slots and the maximum peak loads of dynamic response increase with increasing the impact velocity.