Lateral crashworthiness and optimization for foam-filled double-layer dislocation lattice composite cylinders

Foam materials are extensively used to improve the energy absorption performance of lattice composite structures. This study proposed several innovative types of foam-filled double-layer dislocation lattice composite cylinders (FDDLCCs) and conducted lateral crashworthiness analysis and multi-objective optimization. The lateral compression behavior of the FDDLCCs was examined using a numerical simulation method. The accuracy of the established models was validated through quasi-static lateral compression experiments on the FDDLCCs manufactured using a vacuum infusion molding process (VIMP). Additionally, parametric studies on the FDDLCCs were performed using the validated numerical models. In the quest for optimal FDDLCC designs, metamodels and the non-dominated sorting genetic algorithm II (NSGA-II) algorithm were employed. The specific energy absorption (SEA) and peak crushing force (PCF) were chosen as the two objectives. The results revealed that the three proposed FDDLCC types exhibited favorable energy absorption performance and crashworthiness. Moreover, it was noted that the FDDLCCs without additional enhancement and with clay ceramsite filler demonstrated superior crashworthiness compared to the FDDLCC with double-bracing wires and could serve effectively as energy absorbers.