压杆/试样表面接触变形对SHPB实验应变测量的影响  

Influences of bar/specimen contact surfaces' indentation on strain measurement in SHPB experiments

作　　者：张祖根[1,2] 李英雷[2] 李英华[2] 陈熙盟[1] 

机构地区：[1]兰州大学核科学与技术学院,甘肃兰州730000 [2]中国工程物理研究院流体物理研究所冲击波物理与爆轰物理国防科技重点实验室,四川绵阳621900

出　　处：《爆炸与冲击》2009年第6期573-578,共6页Explosion and Shock Waves

摘　　要：采用SHPB(split Hopkinson pressure bar)实验技术测量了3种不同尺寸纯铁试样的动态压缩应力应变关系,根据实验结果提出一个经验模型,定量分析了SHPB实验中压杆/试样表面接触变形对应变测量的影响。分析表明,在轴向应力平衡条件下,表面的接触变形对弹性段的应变测量影响显著;对塑性段应变测量的影响与试样的强化模量和长度相关,当试样强化模量较大而长度较小时,这种影响将不可忽略,可根据影响量的经验分析模型对应变进行修正。The dynamic compression stress-strain relations of iron specimens with three sizes were obtained with a split Hopkinson pressure bar apparatus. Based on these experimental results, an empirical model was presented to quantitatively describe the influence of bar/specimen contact surfaces＇ indentation on strain measurement in SHPB experiments. This researchshows that the influence on elastic strain is obvious, even when the uneven stress states in specimens eliminated by using pulse shapers; while the influence on plastic strain is related to the hardening modulus and length of the specimen： the influence will be obvious when the hardening modulus is large and the size of the specimen is comparatively small, and the correction for plastic strain is needed.

关 键 词：固体力学 应变修正 SHPB 接触变形 应变测量 

分 类 号：O347[理学—固体力学]