Crashworthiness study of aluminum foam-filled tubular lattice structures based on triply periodic minimal surface metamaterials under lateral crushing

Abstract

Owing to their superior energy absorption capabilities and lightweight characteristics, both aluminum foam and tubular lattice structures based on triply periodic minimal surfaces (named T-TLS) had attracted a lot of attention. However, they had never functioned together in combination. Accordingly, aluminum foam was filled into T-TLS to form foam-filled T-TLS with the aim of enhancing the energy absorption performance, and their mechanical properties under lateral crushing were experimentally and numerically studied. Quasi-static lateral crushing experiments were firstly performed on the empty T-TLS, cylindrical foam filler, and foam-filled T-TLS to obtain deformation modes, force–displacement responses, and crashworthiness parameters. The experimental results indicated that filling aluminum foam changed the deformation mode from a four-hinge mode to a six-hinge mode. Moreover, foam-filled T-TLS displayed significantly enhanced energy absorption performance attributed to the interaction between T-TLS and aluminum foam, as evidenced by higher energy absorption (EA) and specific energy absorption (SEA). Subsequently, validated finite element (FE) models of foam-filled T-TLS were developed to further reveal their crushing responses and crashworthiness performances. Numerical results revealed evident influences of relative densities of T-TLS and foam filler on the deformation mode and energy absorption performance. The competition in stiffness between T-TLS and foam filler led to three distinct deformation modes. Finally, a multi-objective optimization was carried out to derive optimized configurations for foam-filled T-TLS subjected to lateral crushing. In comparison with the baseline designs, the optimal results demonstrated enhanced crashworthiness, with the SEA value increasing by 40.6 to 97.3%.