Sea sponge-inspired designs enhance mechanical properties of tubular lattices

Abstract

The sea glass sponge, a marine organism with a distinctive tubular lattice skeleton, offers inspiration for developing resilient structures with exceptional buckling resistance. Previous work on sponge lattices focuses on mimicking the diagonal feature of the sponge unit cell; however, current understanding on the effects of the tubular three-dimensional arrangement seen in glass sponges is incomplete. This study seeks to leverage the benefits of sea glass sponge structures to enhance the performance of three-dimensional tubular lattices with improved compressive strength and elastic energy absorption. Through a combination of experimental and simulation techniques, we systematically examine the influence of varying cross-sectional shape and geometry of three-dimensional tubular lattice structures. Our experimental findings reveal that the sponge-inspired pattern surpasses all unit cell designs under compression loads. Sponge designs with a hexagonal cross-section exhibit the highest buckling strength, with a 74.9 % improvement over the non-reinforced design and a 39.0 % improvement within sponge designs. Meanwhile, the sponge designs with a circular cross-section show the best energy absorption, achieving a 90.8 % improvement over the non-reinforced design and a 54.0 % increase within sponge designs. Computational results show this novel design achieves improved stress distribution and stability due to the self-reinforcement of the struts’ orientation and reduction of stress concentration at sharp corners, which helps explain these findings. This study motivates the design of sea glass sponge structures for applications such as aerospace, marine, and infrastructure that requires high strength-to-weight ratio and buckling resistance.