Mechanical Analysis Characteristics of Bionic Structure Based on NiTi Alloy Additive Manufacturing

In recent years, the demand for protective structures in aerospace, transportation and other fields has become increasingly intense. In this paper, multi-rotation structure(MRS) and single rotation structure (SRS) are designed based on the microstructure of grass stem cross-section. Selective laser melting (SLM) is used to fabricate the structural model. The mechanical properties of two structures are investigated by numerical simulations and experiments. Results show that the specific absorption energy (SEA) of MRS is 33% higher than SRS. In addition, MRS is tested with cyclic compression and shape recovery experiments, which show the deformation recovery rate of MRS is 96%. Based on the superiority of MRS in mechanical and recovery performance, this paper also analyzes the influence of cell thickness t and cell angle theta on the performance. It is found that the sample with t = 0.45 mm, theta = 60 degrees has the best comprehensive performance. Compared to SRS and initial design structure of MRS, its SEA is improved by 129% and 72.2%, and mean crushing force (MCF) is increased by 330% and 74%. This provides a theoretical basis for the development of new bionic protective structures.