A study on compressive shock wave propagation in metallic foams
A study on compressive shock wave propagation in metallic foams作者机构:State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing China Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of Technology Taiyuan China
出 版 物:《Science China(Physics,Mechanics & Astronomy)》 (中国科学:物理学、力学、天文学(英文版))
年 卷 期:2010年第53卷第2期
页 面:279-287页
核心收录:
学科分类:08[工学] 080102[工学-固体力学] 0801[工学-力学(可授工学、理学学位)]
基 金:supported by the National Natural Science Foundation of China (Grant Nos. 90716005, 10802055) the Natural Science Foundation of Shanxi Province (Grant No. 2007021005)
主 题:aluminum foam heterogeneous intensive pulse loading stress enhancement
摘 要:Metallic foam can dissipate a large amount of energy due to its relatively long stress plateau,which makes it widely applicable in the design of structural crashworthiness. However,in some experimental studies,stress enhancement has been observed when the specimens are subjected to intense impact loads,leading to severe damage to the objects being protected. This paper studies this phenomenon on a 2D mass-spring-bar model. With the model,a constitutive relationship of metal foam and corresponding loading and unloading criteria are presented; a nonlinear kinematics equilibrium equation is derived,where an explicit integra-tion algorithm is used to calculate the characteristic of the compressive shock wave propagation within the metallic foam; the effect of heterogeneous distribution of foam microstructures on the shock wave features is also included. The results reveal that under low impact pulses,considerable energy is dissipated during the progressive collapse of foam cells,which then reduces the crush of objects. When the pulse is sufficiently high,on the other hand,stress enhancement may take place,especially in the heterogeneous foams,where high peak stresses usually occur. The characteristics of compressive shock wave propagation in the foam and the magnitude and location of the peak stress produced are strongly dependent on the mechanical properties of the foam material,amplitude and period of the pulse,as well as the homogeneity of the microstructures. This research provides valuable insight into the reliability of the metallic foams used as a protective structure.