Energy absorption of additively manufactured functionally bi-graded thickness honeycombs subjected to axial loads. (July 2021)

• Record Type: Journal Article
• Authors: Wu, Yaozhong; Sun, Longfei; Yang, Ping; Fang, Jianguang; Li, Weijia
• Is Part Of: Thin-walled structures. Volume 164(2021)
• Publication Date: 2021-07
• Subjects: Energy absorption -- Bi-graded honeycomb -- 3D printing -- Multi-objective optimization -- Active learning; Thin-walled structures -- Periodicals; 690.1
• DOI: 10.1016/j.tws.2021.107810
• Languages: English
• ISSNs: 0263-8231

Abstract

Abstract: A novel bi-graded honeycomb was proposed by introducing both in-plane and out-of-plane thickness gradients into a regular honeycomb. The graded honeycombs were additively manufactured by fused deposition modeling (FDM) with polylactic acid (PLA) and then tested for axial crushing. Numerical simulation models were constructed through LS-DYNA and validated using experiment results. Based on the super folding element (SFE) method, theoretical models of the proposed bi-graded honeycombs were derived and the accuracy for crushing response was validated against the numerical results. Finally, an active learning based multi-objective optimization algorithm was used to seek the optimal design. The results showed that the bi-graded design for honeycomb structures could improve energy absorption capacity and decrease the peak crushing force in the Pareto frontier manner. The specific energy absorption of the optimal bi-graded honeycomb could be 45.6% higher than that of the regular honeycomb while the peak crushing force was controlled at the same level. Highlights: A bi-graded honeycomb was proposed by introducing two direction thickness gradients. Test specimens were additively manufactured and tested for quasi-static crushing. Theoretical models of the proposed bi-graded honeycomb were built. Optimal design was derived by an active learning based multi-objective optimization.