不同单胞形貌和承载方向下蜂窝结构吸能特性及防冲能力评估

为研究单胞形状和承载方向对蜂窝结构力学性能及失稳模式的影响,采用增材制造技术制备了不同蜂窝结构并进行了试验与动态仿真模拟。结果表明:蜂窝结构应力曲线呈四阶段变化趋势;单胞对角承载的六边形蜂窝结构拥有最高的平台应力以及总应变能密度;单胞的坍塌主要原因在于单胞的剪切变形,四边形蜂窝单胞在剪切变形同时胞壁发生严重的屈曲失稳;整体蜂窝结构的失稳模式为基于斜向或横向初始变形带的两类逐层坍塌模式;在大尺寸蜂窝结构仿真模拟中其防冲能力得到了评估,结构吸能值能达10⁵J,满足吸能防冲器要求。所得结论能为液压支架防冲吸能器的设计提供理论依据。

Energy absorption characteristics and impact resistance evaluation of honeycomb structures under different unit cell morphologies and bearing directions

To study the effect of unit cell shape and loading direction on the mechanical properties and buckling mode of honeycomb structures, different honeycomb structures were prepared by additive manufacturing technology, and static load tests and dynamic simulations were carried out. The results show that the stress curve of the honeycomb structure shows a four-stage change trend. The hexagonal honeycomb structure supported by the unit cell diagonally has the highest platform stress and total strain energy density. In addition, the collapse of the unit cell is mainly due to the shear deformation of the unit cell, and the quadrilateral honeycomb unit cell undergoes severe buckling instability during shear deformation. The instability mode of the overall honeycomb structure can be divided into two types: oblique and transverse initial shear bands. In the simulation of large-scale honeycomb structure, its anti-shock ability has been evaluated. The analysis shows that the energy absorption value of the structure can reach 10⁵ J, which meets the requirements of the energy absorption shock absorber. The findings can provide a theoretical foundation for the design of the hydraulic support anti-shock energy absorber.