Static and Dynamic Mechanical Behavior of Lattice Structures of Shape Memory Alloys

Compression of pyramid and hourglass lattice structures was studied. The cross-section of the single rod was square and the main failure modes of the pyramid lattice of two different sizes were elastic flexion and elastic-plastic flexion, respectively. The experiments showed that the limit load and energy absorption per unit volume increased with the loading rate. Loading and unloading experiments were performed on two lattice structures and considering the thermal recovery effects of structures at different temperatures. The results showed that the deformation recovery was stable after 120 degrees C. The simulation of the single rod recovery effect agrees well with the test, indicating that this method is feasible to simulate the thermal recovery effect of shape memory alloy. The dynamic mechanical properties of different pyramid lattice structures were investigated using separated SHPB. The results showed that the shape memory alloy (SMA) lattice structure has an obvious size effect during the impact process. Through the impact process of the high-speed camera, we can see that the dynamic failure process is similar to the static experiment. The core had two failure modes: elastic and inelastic buckling. In the finite element simulation, the Johnson-Cook model in LS-DYNA was used to study the dynamic simulation of different rates, obtain the dynamic stress and strain curve, and analyze the energy absorption characteristics of the structure.