  Lattice structures have tailorable mechanical properties which allows them to
exhibit superior mechanical properties (per unit weight) beyond what is
achievable through natural materials. In this paper, quasi-static and dynamic
behavior of additively manufactured stainless steel lattice cylinders is
studied. Cylindrical samples with internal lattice structure are fabricated by
a laser powder bed fusion system. Equivalent hollow cylindrical samples with
the same length, outer diameter, and mass (larger wall thickness) are also
fabricated. Split Hopkinson bar is used to study the behavior of the specimens
under high strain rate loading. It is observed that lattice cylinders reduce
the transmitted wave amplitude up to about 21% compared to their equivalent
hollow cylinders. However, the lower transmitted wave energy in lattice
cylinders comes at the expense of a greater reduction in their stiffness, when
compared to their equivalent hollow cylinder. In addition, it is observed that
increasing the loading rate by five orders of magnitude leads to up to about
36% increase in the peak force that the lattice cylinder can carry, which is
attributed to strain rate hardening effect in the bulk stainless steel
material. Finite element simulations of the specimens under dynamic loads are
performed to study the effect of strain rate hardening, thermal softening, and
the failure mode on dynamic behavior of the specimens. Numerical results are
compared with experimental data and good qualitative agreement is observed.
