Advances in Engineering Advances in Engineering features breaking research judged by Advances in Engineering advisory team to be of key importance in the Engineering field. Papers are selected from over 10,000 published each week from most peer reviewed journals.
Significance
Lightweight architected cellular structures are ideal candidates for protection against impact-induced damages due to their improved energy absorption capacity and mechanical properties. These structures are usually made up of topologically periodic unit cells defined by the cell spatial geometries. Natural creatures and biological structures display fascinating mechanical performance following many years of evolution to adapt to various harsh environmental conditions. These behaviors have been mimicked to design innovative bio-inspired structures and materials with improved performance than conventional structures.
The design of biologically inspired architected cellular structures like bi-directional corrugated structures with improved properties has attracted research attention. However, manufacturing methods for bio-inspired materials involve complicated architectures, which present a major challenge in engineering and materials science. Additive manufacturing is an effective and robust technology for fabricating complex architected materials with desired properties. For instance, bio-inspired Ti-6Al4V Kagome truss core structures and nacre-like polymer composites manufactured via additive manufacturing technologies exhibit superior performance to honeycombs and constituent polymer materials, respectively.
Previous research findings have shown that the dactyls of Odontodactylus scyllarus is an exceptional damage-tolerant natural material capable of smashing crab exoskeletons, mollusk shells and other hard-shelled prey. Inspired by the microstructural features of the impact region within the dactyls of Odontodactylus scyllarus, Dr. Bo Li, Professor Hua Liu, Dr. Qiao Zhang, Professor Xianfeng Yang and Professor Jialing Yang from Beihang University proposed the design and manufacturing of a novel lightweight biomimetic bi-directional corrugated lattice to enhance the crushing behavior and impact energy absorption capacity. The work is currently published in the journal, Composite Structures.
In their approach, additive manufacturing technology, specifically selective laser sintering method, was used to manufacture the newly proposed structure. The energy absorption behavior and quasi-static compressive properties of the bi-directionally corrugated lattices were numerically and experimentally investigated. Corresponding validated finite element models were used to simulate the compression responses to duplicate the deformation process. Finally, a parametric analysis based on the validated models was carried out to study the effects of wave amplitude, wave number and relative density on the energy absorption and collapse mode behaviors of the multi-layer corrugated lattice structures.
The authors classified the collapse of the corrugated lattices into three failure modes: global buckling, full-folded and transitional mode, all having a strong connection with the specific energy absorption of the lattice structures. For a relatively small wave amplitude to wavelength ratio (A/λ), the corrugated lattice was flat and resulted in full-folded failure mode. However, a global buckling mode was likely to occur for a relatively slender corrugated lattice. For a relatively small wave amplitude to cell-wall thickness ratio (A/h), the lattice was thicker and hard to buckle. However, the lattice was thinner and easier to buckle when the A/h was larger.
The global buckling mode was more likely to occur for lattices with larger wave amplitude and wave numbers. Generally, the transitional and full-folded modes exhibited greater crushing force efficiency, improved energy absorption and better load uniformity than the global buckling mode at equal relative density. Consequently, the bi-directional corrugated lattice exhibited improved energy absorption performance for wave amplitude ranging from 2 – 3 and wave number ranging from 6 – 8. Comparing the three failure modes, the results showed that the corrugated structures collapsing with transitional mode were more suitable and efficient energy absorbers than those collapsing with other failure modes due to significantly higher crushing force efficiency and energy absorption capacity.
In summary, Beihang University researchers reported the design and manufacturing of a novel bio-inspired bi-directional corrugated lattice by selective laser sintering under quasi-static compression load. The resulting lattice exhibited improved impact energy absorption capacity and mechanical properties. In a statement to Advances in Engineering, Professor Xianfeng Yang explained the new bio-inspired corrugated lattice contribute to designing high-performance energy absorbers for different applications.
Reference
Li, B., Liu, H., Zhang, Q., Yang, X., & Yang, J. (2022). Crushing behavior and energy absorption of a bio-inspired bi-directional corrugated lattice under quasi-static compression load. Composite Structures, 286, 115315.
