Mechanical characteristics of superimposed 316L lattice structures under static and dynamic loading

Additive Manufacturing (AM) discrete patterns made of stainless steel 316 L offer potential energy absorption for engineering applications, including blast and impact protection systems and aircraft structure. Herein, three different superimposed stainless steel 316 L lattice structures varying rod diameter are manufactured by selective laser melting (SLM). Compression experiments and split Hopkinson pressure bar (SHPB) tests are conducted to determine the quasi-static and impact behavior of different lattice structures for the strain rate from 10${}^{-3}$ to 1000 s${}^{-1}$. The compressive response, strain rate dependency, and energy absorption capacity of the lattice structures are mechanically characterized. In addition, numerical simulations are conducted to complement the experimental work in which the deformation modes of the lattice under mechanical responses have been studied. The results indicate that vertical truss in structure plays a bearing role in the whole process of compression, which is better than inclined truss structures. Due to the combined effect of two deformation modes in the superimposed structure, it has shown superior energy absorption capacity compared with other structures. The superiority of the superimposed structure provides a new idea for the design of lattice structure. (© 2021 Wiley-VCH GmbH)