不同加载方式下减震器填充材料力学性能实验研究

Experimental Investigation on Mechanical Performance of Shock Absorber Filled Materials by Different Loading Methods

中文关键词:  高密度泡沫铝  力学性能  吸能特性  准静态压缩  围压压缩  落锤冲击

英文关键词:high-density aluminum foam  mechanical performance  energy absorption property  quasi-static compression  confined compression  drop-hammer impact

中文摘要:

      目的 研究不同加载方式下高密度泡沫铝的力学行为和吸能特性，为减震器结构优化设计提供指导。方法 利用MTS万能材料试验机和Instron 9350材料冲击试验机，分别对高密度泡沫铝板材表面纵向(x方向)、横向(y方向)和厚度方向(z方向)切取的试样开展准静态压缩、围压压缩以及落锤冲击实验，基于电测法获取高密度泡沫铝的压缩载荷-位移曲线，并通过理论计算得到高密度泡沫铝的吸能特性结果。结果 准静态压缩载荷作用下，高密度泡沫铝制备的随机性导致其沿3个方向加载的力学性能出现小范围波动;围压压缩和落锤冲击载荷作用下，不同加载方向对高密度泡沫铝的力学性能和吸能特性影响可忽略不计。结论 相比于准静态压缩加载，高密度泡沫铝在围压压缩加载下的塑性平台阶段具有明显的强化效应。对于落锤冲击加载，高密度泡沫铝的平台应力、密实化应变和吸收能量呈现一定的加载速率相关性，但其吸能效率与加载速率无关。

英文摘要:

      The work aims to explore the mechanical performance and energy absorption property of high-density aluminum foam under different loading methods, so as to provide guidance for the optimal design of the shock absorber structure. Quasi-static compression, confined compression and drop-hammer impact tests were conducted on the specimens cut in longitudinal (x direction), transverse (y direction) and thickness direction (z direction) on the surface of a high-density aluminum foam plate by MTS universal testing machine and the Instron 9350 impact testing machine. The compressive loading-displacement curves of the high-density aluminum foam were obtained based on the electrodynamic method, and the results of the energy-absorption property of high-density aluminum foam were determined through theoretical calculations. Under quasi-static compression loading, the mechanical properties of high-density aluminum foam loaded along the three directions fluctuated within a small range due to the randomness of its preparation. Under confined compression and drop-hammer impact loading, the influence of different loading directions on the mechanical performance and energy absorption property of high-density aluminum foam could be negligible. Compared with quasi-static compression loading, the plastic plateau stage of high-density aluminum foam under confined compression loading has an obvious strengthening effect. For the drop-hammer impact loading, the plateau stress, densification strain and absorbed energy of high-density foam aluminum exhibit a certain correlation with the loading rate, but its energy absorption efficiency is independent of the loading rate.