Energy absorption of foam-filled TPMS-based tubular lattice structures subjected to quasi-static lateral crushing

Aluminium foam and TPMS-based tubular lattice structures (T-TLS) were of interest due to their superior energy absorption capabilities and inherent lightweight characteristics. However, their synergistic functionality in a composite form remained unexplored. In pursuit of augmenting the crashworthiness characteristics, aluminum foam was filled into T-TLS to form foam-filled T-TLS. FE models were established and validated using lateral crushing experiments. Foam-filled T-TLS exhibited higher energy absorption (EA) compared to the sum of empty T-TLS and foam filler, primarily attributed to the interaction between T-TLS and foam filler. Compared to single circular filled tubes (SCFT) with the same outer sizes and mass, foam-filled T-TLS revealed markedly enhanced crashworthiness, with EA and SEA values being 3.5-3.9 times and 4.0-4.7 times that of SCFT, respectively. Subsequently, parametric investigations underscored the evident influences of relative densities of T-TLS and foam filler, tube thickness and diameter on crashworthiness of foam-filled T-TLS. Finally, a multi-objective optimization was performed to derive optimized configurations by using non-dominated sorting genetic algorithm II (NSGA-II) and radial basis function (RBF) metamodels. In comparison with the baseline designs, the optimal results demonstrated significant enhancements in crashworthiness, with SEA increasing by 173.3 to 206.6 %. The present work provided a new paradigm in the design and development of advanced energy absorbers characterized by high-efficiency energy dissipation under lateral impact scenarios.