Compression Behavior and Impact Energy Absorption Characteristics of 3D Printed Polymer Lattices and Their Hybrid Sandwich Structures

In this paper, the compression behavior of four lattice topologies with body-centered and face-centered structures was first analyzed numerically based on the material model of 3D printed polylactic acid (PLA). To enhance the interface bonding properties between the AZ31B Mg face sheets and the PLA lattice cores, the skin-core interface was preprocessed by 3D printing microgrooves on PLA pre-pregs. The interface parameters of the heterogeneous bonding layer were then obtained through DCB and ENF experiments. The impact simulation by using ABAQUS/Explicit with a self-written VUMAT subroutine for the enhanced interfacial layer was finally carried out for the hybrid Mg alloy skin and PLA lattice-core sandwich panels with high energy absorption characteristics under static compression. The results have shown that the BCCZ and F(2)CCZ lattice configurations with Z-direction pillars exhibit better quasi-static compression characteristics compared with the BCC and F2CC structures. Interlayer fracture toughness values G(IC) and G(IIC) of the skin-core interface can reach up to 0.63 and 7.02 kJ/m(2), respectively. Under low-velocity impact, the hybrid sandwich panels with F(2)CCZ lattice cores exhibit better impact resistance and energy absorption capacity than those of the BCCZ lattice sandwich panels.