冲击载荷下圆环纵向压缩力学行为研究  

Investigation on Mechanical Behaviour of a Ring Subjected to Longitudinal Compression Impact Loading

作　　者：杨茨 徐松林[1] 易洪昇 

机构地区：[1]中国科学技术大学中国科学院材料力学行为与设计重点实验室,安徽合肥230027

出　　处：《实验力学》2014年第1期18-25,共8页Journal of Experimental Mechanics

基　　金：国家自然科学基金(11272304)资助

摘　　要：选用外径、内径和高度三者比值为6∶3∶2的铝合金圆环试件作为研究对象,在粗磨、细磨和润滑三种端面粗糙条件下,利用SHPB实验方法研究了其纵向动态压缩行为。实验结果表明:随着端面摩擦系数的增大,对应的屈服强度和硬化强度增大明显。同时,圆环纵向压缩应力应变曲线有一个明显的应力下降段。其原因是圆环在塑性压缩过程从内而外发生了动态塑性失稳。由于端面应力不均匀和压缩过程端面摩擦系数不均匀变化,试件前后端面的压缩变形明显不一致。数值模拟分析了不同表面粗糙情况下的圆环纵向压缩过程,得到了和实验相类似的现象。Taking aluminum alloy ring specimens with ratio of 6 ： 3 ： 2 among outer diameter, inner diameter and height as study object, under three end face roughness conditions including rough grinding, fine grinding and lubricated, its longitudinal dynamic compression behavior was experimentally investigated based on SHPB devices. Results show that along with the increase of end face friction coefficient, the corresponding yield strength and hardening strength increase significantly. At the same time, there is an obvious stress drop in stress-strain curve of ring＇s longitudinal compression. The explanation for this stress drop maybe is the result of dynamic plastic instability propagated from inside to outside during plastic compression process. Specimen＇s compression deformations at front and rear end faces are apparent inconsistent due to the uneven end face stresses and uneven change of friction coefficient during compression process. The longitudinal compression process of the ring was numerically simulated under different surface roughness conditions. The obtained results are similar to experimental one.

关 键 词：冲击动力学 分离式霍普金森压杆 圆环纵向压缩 端面摩擦效应 

分 类 号：O347[理学—固体力学]