(1. 寧波大學(xué)機(jī)械工程與力學(xué)學(xué)院，寧波，315211；
2. 北京理工大學(xué)機(jī)電學(xué)院，北京，100081)
摘 要: 采用扁平閉合帽形試樣，利用材料試驗機(jī)(MTS)和分離式霍普金森壓桿(SHPR)作為加載手段，結(jié)合數(shù)字圖像相關(guān)法(DIC)和金相分析，研究準(zhǔn)靜態(tài)和動態(tài)加載下帽型試樣發(fā)生受迫剪切的破壞特征和力學(xué)響應(yīng)。結(jié)果表明：準(zhǔn)靜態(tài)加載下失效由塑性損傷累積導(dǎo)致的裂紋形成并擴(kuò)展引起；動態(tài)加載下，失效模式為絕熱剪切失效。準(zhǔn)靜態(tài)加載下，剪切變形區(qū)始終保持一定寬度；而動態(tài)加載下，剪切區(qū)寬度逐漸減小，直到高度局部化的絕熱剪切帶形成，且準(zhǔn)靜態(tài)加載剪切區(qū)寬度明顯大于動態(tài)加載剪切寬度。
關(guān)鍵字: TA2鈦合金；準(zhǔn)靜態(tài)；動態(tài)；裂紋；絕熱剪切；剪切區(qū)寬度
（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
