CAJ | 학술논문

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.
채용SHPB(split Hopkinson pressure bar)실험기술측량료3충불동척촌순철시양적동태압축응력응변관계,근거실험결과제출일개경험모형,정량분석료SHPB실험중압간/시양표면접촉변형대응변측량적영향.분석표명,재축향응력평형조건하,표면적접촉변형대탄성단적응변측량영향현저;대소성단응변측량적영향여시양적강화모량화장도상관,당시양강화모량교대이장도교소시,저충영향장불가홀략,가근거영향량적경험분석모형대응변진행수정.
The dynamic compression stress-strain relations of iron specimens with three sizes were obtained with Split Hopkinson Pressure Bar apparatus. Based on these experimental results, an empirical model was presented which can quantitatively describe the influence of bar/specimen contact surfaces' indentation on strain measurement in SHPB experiment. This research shows that the influence on elastic strain is catastrophic, even when the uneven stress state in specimen eliminated by using pulse shaper; while the influence on plastic strain related to hardening modulus and the 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.