Experimental evaluation of hybrid lattice structures subjected to blast loading

Abstract

Lattice structures have shown potential for efficient protection against dynamic loading events, especially during high-strain rate scenarios such as a blast. Additive manufacturing enables the design of complex geometries to optimise lattice architecture and increase blast resistance. However, the lack of experimental data related to blast-resistant lattice structures poses challenges in developing and validating theoretical and numerical models. This study aims to design blast-resistant lattice structures that can improve protection efficiency at wider applicability in high-strain rate loadings. For that, hybrid-layered Triply Periodic Minimal Surfaces (TPMS) lattice structures were systematically designed using a Design of Experiments (DoE) approach and manufactured using additive manufacturing (AM). The Blast Hopkinson Pressure Bar (BHPB) rig was used to compare the influence of different lattice topologies and relative densities on energy absorption when specimens were subjected to compressive blast loading. High-speed imaging was utilised to measure transient deformation in addition to the load transferred through the specimens. The experimental results indicated that the BHPB rig could appropriately measure the energy absorption of compressive structures subjected to shockwave loading. Additionally, the results demonstrated that TPMS topology and relative density changes substantially affect its performance. The DoE approach was utilised to predict the performance improvements of layered-hybrid lattice structures, providing valuable data for blast protection specialists and engineers designing AM lattice structures to resist blast loading.