矩形与X形组合蜂窝异面缓冲性能的研究

Cushioning Performance of Rectangular and X-shaped Combined Honeycomb

目的为了研究矩形与X形组合蜂窝材料在异面冲击载荷下的缓冲吸能特性,建立矩形与X形组合蜂窝的有限元模型,分析在不同冲击条件下组合蜂窝结构的能量吸收、动态平台应力及其变形模式。方法借助ANSYS/LS-DYNA软件建立可靠的基于单元阵列的异面缓冲性能有限元分析模型,基于该模型在不同结构参数和冲击速度下进行异面动态冲击仿真分析,将结果以图表等形式进行展示。结果组合蜂窝结构的异面缓冲性能较矩形、X形蜂窝结构更为优异。当相对密度一定时,随着扩展角的增大,组合蜂窝结构的缓冲性能会有一定提升。扩展角为90°的组合蜂窝结构与扩展角为70°、50°和30°的组合蜂窝相比,其单位体积能量吸收值分别提高了3.77%、4.53%和26.95%。异面动态平台应力与冲击速度和结构参数之间,可用某一确定的曲线关系进行拟合。结论矩形与X形蜂窝之间会产生较强的耦合效应,使组合蜂窝结构的接触载荷和总能量吸收值均大于两者之和;冲击速度对变形模式的影响较大,在冲击载荷下存在3种变形模式,但壁厚的改变对变形模式并未产生明显影响。当扩展角和冲击速度一定时,组合蜂窝异面动态平台应力与壁厚边长比呈二次曲线关系;给定扩展角和壁厚时,异面动态平台应力与冲击速度呈一次曲线关系。

The work aims to establish a corresponding finite element model to study the ability of out-of-plane cushioning energy absorption of the rectangular and X-shaped combined honeycomb and analyze the energy absorption,dynamic plateau stress and deformation mode of combined honeycomb under different impact conditions.A reliable finite element model was established based on the array of cells with ANSYS/LS-DYNA software.Then,on basis of this model,the simulation analysis of out-of-plane dynamic impact was carried out under different structural parameters and impact velocities,and the results were displayed in the form of charts.The out-of-plane cushioning performance of combined honeycomb was better than those of the rectangular and X-shaped honeycombs.When the relative density was fixed,the cushioning performance of the combined honeycomb became better with the increase of expanding angle.For the combined honeycomb with the expanding angle of 90°,the volume energy absorption value was increased by 3.77%,4.53%and 26.95%,in comparison with those of 70°,50°and 30°,respectively.Some curves could be used to fit the correlations of out-of-plane dynamic plateau stress with configuration parameters and impact velocity.There is a strong coupling effect between the rectangular and X-shaped honeycomb,and the values of contact load and total energy absorption are greater than the sum of both.The impact velocity has a great effect on the deformation modes of combined honeycomb,and three deformation modes are observed.However,the cell wall thickness has no obvious effect on the deformation mode.When the expanding angle and impact velocity are constant,the relationship between the out-of-plane dynamic plateau stress and the ratio of cell wall thickness to edge length of the combined honeycomb is shown as a quadratic curve.When the expanding angle and cell wall thickness are fixed,there is a linear relationship between the out-of-plane dynamic plateau stress and impact velocity.