高温高应变率下材料拉伸性能测试的一种新方法

为了实现高温环境下材料高应变率动态拉伸实验技术,将分离式Hopkinson杆直接拉伸装置中试样与拉杆的螺纹连接形式变成楔形连接形式,并加装了气动同步装置系统。这样,在对试样加高温时,能使靠近试样的入射和透射杆端处于较低温度。当撞击管向传递法兰运动时,气动同步装置瞬间拖动透射杆和试样,使两者之间的间隙为零,此时沿入射杆传递的入射波同时对试样拉伸加载。经实验验证,此方法可以有效实现材料高温高应变率拉伸加载。

A New Method of Tensile Performance Testing for Materials at High Temperature and High Strain Rate

In order to realize the dynamic tensile test of materials at high temperature and high strain rate, some modifications are required for the traditional split Hopkinson tensile bar: changing connection way between the specimen rod and the bar from threaded connection to wedge groove connection form and installing a pneumatic synchronization device system. These modifications enable the end between incident bar and transmission bar, which is closed to the specimen, is at a low temperature, while the specimen is at the desired high temperature. When the impact tube is moving towards the transfer flange, the pneumatic synchronization device system will drag the transmission bar and the specimen instantly to make the gap between the transmission bar and specimen close. Just at this time, the incident tensile pulse reaching the interface between the incident bar and the specimen begins to load. Experimental results show that these modifications are valid by dynamic tensile test of materials at high temperature and high strain rate.