Abstract

The development of additive manufacturing and lattice structures has created opportunities for the development of lightweight impact–absorption structures that can overcome most constraints of previously used materials such as expanded polystyrene foams. However, for the successful application of such structures, the effects of their variables in their mechanical performance must be established. In this study, the mechanical properties and energy absorption of thermoplastic sheet gyroid structures were investigated and compared with the performance of current materials. Consequently, the specimens were tested after changing the main variables, i.e., cell size and volume fraction, of various thermoplastic materials such as acrylonitrile butadiene styrene, polylactic acid, thermoplastic polyurethane, and polyamide 12. Finally, they were tested in a quasi-static compression test and their deformation stages were photographed. The stress–strain curves of all materials changed after adopting the sheet gyroid structure, exhibiting three distinct regions: linear elastic, long collapse plateau, and densification that made them particularly applicable for energy absorption. Volume fraction affected the layer collapse. The elastic geometrical stiffness increased for higher volume fractions and smaller cells. In addition, the peak and plateau stresses increased at higher volume fractions, and while smaller cells were not directly affected. Additionally, the area under the curves increase with the volume fraction; hence, for most materials, specific energy absorption was larger for higher volume fractions. The constituent material properties contributed significantly to the structural behavior, exhibiting three primary deformation mechanisms, i.e., elastomeric, elastic–plastic, and elastic–brittle, resulting in a wide spectrum of properties for each application requirement. The comparison of the optimal properties with the expanded polystyrene demonstrated the ability of sheet gyroid structures to overcome most of its challenges, exhibiting a superior specific energy absorption, ability to withstand various impacts, letting air flow in its all axes, and being recyclable. Thus, sheet gyroid structures can be considered promising alternatives.

摘要

增材制造和晶格结构的发展为轻质冲击吸收结构的开发创造了机会，这些结构可以克服以前使用的材料（如发泡聚苯乙烯泡沫）的大多数限制。然而，为了成功应用此类结构，必须确定其变量对其机械性能的影响。在这项研究中，研究了热塑性片状陀螺结构的机械性能和能量吸收，并与当前材料的性能进行了比较。因此，在改变各种热塑性材料（如丙烯腈丁二烯苯乙烯、聚乳酸、热塑性聚氨酯和聚酰胺 12）的主要变量（即泡孔尺寸和体积分数）后，对试样进行了测试。最后，它们在准静态压缩试验中进行了测试，并拍摄了它们的变形阶段。采用片状陀螺结构后，所有材料的应力-应变曲线都发生了变化，表现出三个不同的区域：线弹性、长塌陷平台和致密化，这使得它们特别适用于能量吸收。体积分数影响层塌陷。对于更高的体积分数和更小的单元，弹性几何刚度增加。此外，峰值和平台应力在较高的体积分数下增加，而较小的细胞没有直接影响。此外，曲线下的面积随着体积分数的增加而增加；因此，对于大多数材料，体积分数越高，比能量吸收越大。组成材料特性对结构行为有很大贡献，表现出三种主要的变形机制，即弹性体、弹塑性和弹性脆性，从而为每种应用要求提供广泛的特性。与膨胀聚苯乙烯的最佳性能比较表明，片状陀螺结构能够克服其大部分挑战，表现出卓越的比能量吸收能力，能够承受各种冲击，让空气在其所有轴上流动，并且可回收利用。因此，片状陀螺结构可以被认为是有希望的替代品。与膨胀聚苯乙烯的最佳性能比较表明，片状陀螺结构能够克服其大部分挑战，表现出卓越的比能量吸收能力，能够承受各种冲击，让空气在其所有轴上流动，并且可回收利用。因此，片状陀螺结构可以被认为是有希望的替代品。与膨胀聚苯乙烯的最佳性能比较表明，片状陀螺结构能够克服其大部分挑战，表现出卓越的比能量吸收能力，能够承受各种冲击，让空气在其所有轴上流动，并且可回收利用。因此，片状陀螺结构可以被认为是有希望的替代品。