Effects of Strain Rate on the Mechanic Performance of Lattice Materials

Split Hopkinson pressure bar (SHPB) was utilized to explore the effects of loading strain rate on the dynamic compressing strength of the titanium alloy lattice material. Results reveal that the yield strength of alloy lattice material reaches 342 MPa initially and then drops to 200 MPa before it rebounds to 252 MPa while the loading strain rate correspondingly increases from the static value 1 401/s to 2 084/s. Numerical simulations were then carried out to explore the possible reason underlying. Results show that the lattice structure changed the stress distribution and caused significate stress concentration at finite strain with high strain rate. It is believed that the strain rate strengthening effect and layer-wise failure mode are the main reasons of the above mechanical properties change.