Design and Energy Absorption Performance of Morning Glory-Inspired Lattice Structures via Topology Optimization

Lattice structures inspired by biological systems have garnered considerable research interest for their outstanding strength-to-weight ratios and superior energy absorption capabilities, making them particularly valuable for aerospace, biomedical, and protective engineering applications. Inspired by the distinctive geometric morphology of morning glory flowers, this study presents two novel bioinspired unit cells of the four-petal morning glory-inspired structure (FMGS) and the six-petal morning glory-inspired structure (SMGS). Corresponding lattice structures, namely the four-petal morning glory-inspired lattice structure (FMGLS) and the six-petal morning glory-inspired lattice structure (SMGLS), were subsequently developed. Lightweight designs were achieved through topology optimization, with response surface methodology applied to optimize geometric parameters. Specimens fabricated using Digital Light Processing underwent quasi-static compression testing, complemented by finite element simulations that accurately predicted experimental deformation and energy absorption behavior. The results show that SMGS has higher specific energy absorption (SEA) and comprehensive mechanical properties. These advantages were further amplified in the lattice structures. Specifically, compared with several classical lattice designs of similar relative density, the proposed SMGLS demonstrated substantially enhanced energy absorption performance. The results indicate the six-petal morning glory-inspired structure as a highly promising candidate for lightweight, impact-resistant engineering applications, demonstrating superior energy absorption efficiency and mechanical robustness.