梯度蜂窝面外动态压缩力学行为与吸能特性研究

MECHANICAL BEHAVIOR AND ENERGY ABSORPTION OF GRADED HONEYCOMB MATERIALS UNDER OUT-OF-PLANE DYNAMIC COMPRESSION

蜂窝材料具有优异的抗冲击吸能特性.为进一步提高蜂窝材料的比吸能与压缩力效率,提出了一种几何参数或材料参数沿厚度方向梯度渐变的蜂窝材料模型,并针对六边形蜂窝构型研究了胞元壁厚和屈服强度梯度变化的蜂窝材料在面外动态压缩载荷下的力学行为与吸能特性.研究结果表明,通过调控梯度变化的指数,胞元壁厚或母体材料屈服强度的梯度设计均可有效降低初始峰值应力,并使蜂窝材料的比吸能和压缩力效率同时增大.研究结果可为蜂窝材料的防撞性优化设计提供新的思路.

Honeycomb materials are of good energy absorption performance under impact loading. To further improve their specific energy absorption and crash load efficiency, a new honeycomb model is proposed here, of which one geometry parameter or material parameter varies gradually along the honeycomb thickness direction. Based on the hexagonal configuration, the mechanical behavior and energy absorption of honeycombs with cell wall thickness or yield strength of based material varying gradually along the thickness direction are investigated under dynamic compression. It is demonstrated that by adopting proper grading exponents, honeycomb materials with graded distribution of cell wall thickness or yield strength of based material can bring down the initial peak stress as well as increase the specific energy absorption （SEA） and crash load efficiency （CLE）. These results may provide new ideas to optimal design of honey- comb materials for energy absorption.