Multi-objective optimisation of bio-inspired lightweight sandwich structures based on selective laser melting

Abstract

ABSTRACT Multi-objective optimisation of the bio-inspired lightweight structure is developed by response surface methodology (RSM) and non-dominated sorting genetic algorithm II (NSGA-II) for future applications in the aerospace and military fields. Multilayer bio-inspired sandwich structures of Ti6Al4V alloy are designed and fabricated by selective laser melting (SLM). Results show that the bio-inspired sandwich structures can be optimized by RSM and NSGA-II with a relative error rate of experiment and response value less than 10%. The bio-inspired sandwich structures with different core-arranged configurations were destroyed layer by layer under out-of-plane loadings with a primary failure mode of the core breaking. Increasing the layer number of cores can improve the comprehensive mechanical performances of multilayer bio-inspired sandwich structures with cross-arranged configurations but will decrease the energy absorption capacity of those with parallel-arranged configurations. Furthermore, the two-layered bio-inspired sandwich structure under cross-arranged configurations has the most excellent comprehensive performances with the specific energy absorption of 9.16 × 103 J/kg and the energy absorption of 154.80 J, respectively.