泡沫铝材料参数反求及其填充锥形薄壁管的吸能性能研究

摘要

为了研究一种商业化生产的泡沫铝力学性能并对其填充结构进行仿真模拟,基于材料的准静态压缩试验和材料本构模型进行了泡沫铝和铝合金材料参数反求,并采用试验数据验证了所得材料参数的正确性.运用有限元软件LS-DYNA进行数值分析,研究了壁厚、锥角和填充泡沫铝密度等设计参数对泡沫铝填充锥形薄壁管吸能特性的影响.结果表明,利用材料反求的方法可获得准确的材料参数;泡沫铝密度和壁厚对平均力的影响更为显著,相比于锥角更易控制能量吸收;管壁厚度是影响初始峰值力的主要因素;填充泡沫铝后不仅能够改善薄壁管的变形情况、增大比吸能,且对初始峰值力的影响较小.%In order to study the mechanical properties of a commercial aluminum foam and simulate its filling structure.The material parameters of aluminum foam and alloys are identified based on the material quasi-static compression experiments and material constitutive model.The identified results are validated by using the experiment data.Then,as the composite structure,the parameter analysis of the foam-filled tube is conducted,such as thickness,cone angle and foam density.The finite element code LS-DYNA is used to study effect of these factors on the energy absorbed prosperity of foam-filled taper thin-walled tube via virtual test.The results show that the identification method can obtain the accurate material parameters,aluminum-foam density and tube thickness are the main factors on the average force and easier to control the energy absorption than that via cone angle.Through the computer simulation,the tube thickness is the main factor for influencing the initial peak force.The filling of aluminum foam can not only improve the thin-walled tube's deformation mode,increase the specific energy absorption,but also has few influence on the initial peak force.The present results can provide the reference for the structural design of energy absorber such as automobile energy absorption box.