(1. 宁波大学机械工程与力学学院，宁波，315211；
2. 北京理工大学机电学院，北京，100081)
摘 要: 采用扁平闭合帽形试样，利用材料试验机(MTS)和分离式霍普金森压杆(SHPR)作为加载手段，结合数字图像相关法(DIC)和金相分析，研究准静态和动态加载下帽型试样发生受迫剪切的破坏特征和力学响应。结果表明：准静态加载下失效由塑性损伤累积导致的裂纹形成并扩展引起；动态加载下，失效模式为绝热剪切失效。准静态加载下，剪切变形区始终保持一定宽度；而动态加载下，剪切区宽度逐渐减小，直到高度局部化的绝热剪切带形成，且准静态加载剪切区宽度明显大于动态加载剪切宽度。
关键字: TA2钛合金；准静态；动态；裂纹；绝热剪切；剪切区宽度
（1. Faculty of Mechanical Engineering and Mechanics, Ningbo University, Ningbo 315211, China;
2. School of Mechatronical Engineering, Beijing Institute of Technology, Beijing100081, China）
Abstract:Combined with the digital image correlation (DIC) and metallographic methods, a flat-hat-shaped specimen was loaded by the material testing system (MTS) and splited Hopkinson pressure bar (SHPB) to study the quasi-static and dynamic forced shear failure behavior and mechanical response of commercial pure titanium (CP-Titanium). The results show that the quasi-static failure is caused by the accumulation of plastic damage, while the dynamic collapse is caused by adiabatic shear localization. Furthermore, the shear zone approximately keeps a constant width, the width of shear zone continually narrowdown from a plastic region to a narrow band, namely adiabatic shear band, under dynamic loading. Moreover, the width of quasi-static loading is evidently lager than that of the dynamic loading.
Key words: TA2 titanium alloy; quasi-static; dynamic; crack; adiabatic shear band; shear zone
