高温分离式Hopkinson压杆技术及其应用

The Split Hopkinson Pressure Bar Technique of High temperatures and Its Application

本文介绍了在分离式Hopkinson压杆装置上通过使用一种气动同步机构,实现对试样进行高温高应变率加载的技术。利用此技术仅对试样加高温度而保持入射杆和透射杆与试样脱离且处在较低温度,到预定温度时,借助气动同步机构使入射杆、透射杆与试样接触并同时实现对试样加载。利用波形抑制技术,仅对试样实现一次加载,入射杆中的后续二次加载波通过反作用质量块吸收。通过这些技术的结合,1)可以进行材料在高温高应变率下应力应变测试;2)可以测试材料在高应变率不同温度下的等温曲线;3)可以间接对材料的塑性功热转换系数进行测试;4)可以进行不同温度高应变率下的中断跳跃试验等。在文中给出了一些典型的试验曲线和结果,并对测试方法和结果进行了分析讨论。

In the present paper, a kind of pneumatically synchronous mechanism is used to the split Hopkinson pressure bar, the technique of high strain-rate loading for a sample at high temperature is introduced. With the aid of this technique, only the sample is heated; the incident and transmission bars keeping a distance with the sample are in lower temperature. When the temperature goes up to the prearranged temperature, the transmission bar is moved to the sample and touched with the sample and incident bar, at the same time, the sample is loaded by this synchronous mechanism. Using the technique of trapping the 2nd reloading pulse, the sample only is loaded once; the 2nd and following pulses along incident bar are absorbed by reaction mass. The following tests can be performed by combining the above techniques. 1） The stress-strain curves of materials at high temperatures and high strain rates can be measured. 2） The isothermal curves of materials at high strain rates and different temperatures can also be measured. 3） The coefficient of heat conversion from plastic work to heat can be indirectly measured. 4） The interrupting or jumping tests at higher strain rates and different temperatures can be performed. Some typical curves and testing results are presented in this paper. The measuring methods and results are discussed and analyzed.