基于TPU材料层级结构的优化设计及吸能特性

Optimized Design and Energy Absorption of TPU Material Based on Hierarchical Structure

选择柔性热塑性聚氨酯(TPU)为原料制备实验试样。基于面心立方层级结构,改变结构的直梁样式、间距,并将蜂窝结构层引入结构中,通过实验和有限元分析,研究层级结构在准静态加载下的变形模式和吸能特性。实验结果与有限元分析得到的载荷-位移曲线吻合较好。结果表明:与初始面心立方层级结构相比,增大直梁的振幅,调整直梁间距为2 mm,即增加塑性铰个数时,又或将蜂窝结构层引入层级结构,可以大幅提高层级结构的能量吸收性能;减小间距、增多塑性铰数目对改善层级结构吸能能力的效果最优;D-1构型与M-1构型相比,比吸能提高了46%;调整塑性铰位置时,层级结构会发生屈曲,不利于层级结构的能量吸收;与M-1构型相比,D-2和D-3构型的比吸能分别降低了27%和34%。

In this paper,the deformation behavior and energy absorption performance of the hierarchical structure were investigated based on the face-centered cubic hierarchical structure to change the amplitude and distance of the hierarchical structure’s straight beams and introduce the honeycomb structure layer.The quasi-static compression behavior of the proposed hierarchical structure was carried out through finite element methods(FEM)and experimental tests.Thermoplastic polyurethanes(TPU)as the raw material was used to prepare the experimental samples.The force-displacement curves obtained from the FEM and experimental tests are consistent with each other.Compared with the original face-centered cubic layered structure,the conclusion can be obtained:the new hierarchical structure has better energy absorption performance than the face-centered cubic hierarchical structure.The introduction of sinusoidal beams,the increase of plastic hinges,the adjustment of the angle between layers,and the introduction of honeycomb structure layers can enhance the energy absorption ability.