目的 深入理解Ti-6Al-4V钛合金的冲击断裂行为。方法 利用一级轻气炮在177.7~298.7 m/s的速度下开展Taylor杆撞击实验，获取Ti-6Al-4V钛合金Taylor杆在不同撞击速度下的失效行为;基于修正的MJC塑性模型和Lode参数相关的Modified Mohr-Coulomb(MMC)断裂准则建立撞击实验的有限元计算模型，并对Ti-6Al-4V钛合金Taylor杆的冲击断裂行为进行预报和分析。结果 随着撞击速度的提高，Ti-6Al-4V钛合金Taylor杆依次发生镦粗、剪切开裂和破碎3种变形和断裂模式;采用Lode相关的MMC断裂准则可以合理预报Ti-6Al-4V钛合金Taylor杆的塑性变形和断裂行为。结论 尽管具有明显的单元尺寸敏感性，采用Lode相关的MMC断裂准则仍可合理预报Ti-6Al-4V钛合金在Taylor撞击中的冲击失效行为，压-剪应力状态在Ti-6Al-4V钛合金Taylor杆的失效过程中占据主导地位。

The work aims to investigate the impact fracture behavior of Ti-6Al-4V titanium alloy. Taylor impact tests were conducted with a one-stage gas gun in an impact velocity range of 177.7-298.7 m/s to obtain the fracture behavior of Ti-6Al-4V titanium alloy Taylor rod under different impact velocities. Subsequently, a finite element model was built based on a modified MJC plasticity model and a Lode dependent modified Mohr-Coulomb (MMC) fracture criterion, and was then used to predict and analyze the fracture behavior of Ti-6Al-4V titanium alloy Taylor rod. Upsetting, shear cracking and fragmentation could be observed with the increasing impact velocities and the Lode dependent MMC fracture criterion could reasonably predict the plastic deformation and fracture behavior of the Ti-6Al-4V titanium alloy Taylor rod. In spite of mesh size sensitivity, the Lode dependent MMC fracture criterion can reasonably predict the impact fracture behavior of Ti-6Al-4V titanium alloy Taylor rod. Compression-shear is the dominant stress state during the fracture behavior of Ti-6Al-4V titanium alloy Taylor rod.