Hopkinson杆三点弯曲试验中试样与支座接触状态分析

DISCUSSION ON CONTACT SITUATION OF SPECIMEN WITH SUPPORTS IN HOPKINSON BAR THREE-POINT BENDING TEST

分析Hopkinson杆动态断裂试验中试样与支座的接触状态。研究表明,试样与支座的接触状态取决于试样几何和材料性能参数。在按现行三点弯曲试验方法进行的试验中,确实存在试样与支座脱离接触的现象,并且试样在支座开始受力前起裂。因此,所谓Hopkinson杆三点弯曲试验实际上是单点弯曲试验。并给出标准Charpy试样在Hopkinson杆动态断裂试验中试样与支座之间保持接触的条件。

The contact situation of specimen with supports in the dynamic fracture test with the apparatus of split Hopkinson bar has been analyzed. The results indicate that the contact situation of specimen with supports is determined by specimen dimension and material properties. In the standard dynamic fracture test of three-point bend, the phenomenon of loss contact between specimen and supports exists and the crack of specimen initiates before supports beginning to be stressed. Therefore, the so-called three-point bending experiment is in fact the one-point bending experiment. And the conditions of Charpy specimen keeping in touch with supports have been obtained.