用短棒试件测试无烟煤的动态断裂韧度

介绍了设计的新型圆台式压头及配套的衬片加载部件，推导了采用新的加载部件进行冲击断裂实验时的断裂韧度计算公式。采用SHPB实验装置，用新加载部件对带有V形切口的无烟煤短棒试件的裂纹尖端施加拉伸载荷，测定了无烟煤的动态断裂韧度。结合准静态实验数据得到了无烟煤断裂韧度随加载率lg(dF/dt)的总体变化规律:当lg(dF/dt)6时，无烟煤的断裂韧度缓慢上升，但当lg(dF/dt)6以后，无烟煤的断裂韧度随加载率的增加快速增大。实验表明:圆台式加载比刀刃式加载更具优越性和适应性，是测试岩石类材料短棒试件动态断裂韧度较好的方法。

Determining dynamic fracture toughness of anthracite by using a short-rod specimen

This paper presents a newly-designed loading truncated cone, its associated two gland bushes, and an analytical formula for testing dynamic fracture toughness of anthracite. The impact fracture tests were carried out by using the SHPB and the newly-designed loading components. The dynamic fracture toughness of anthracite was measured on  the short-bar anthracite specimens with the V-shaped notch. The relationship between the fracture toughness and loading rate lg(dF/dt) of anthracite was obtained by combining with the experimental data gained from the quasi-static tests. The fracture toughness of anthracite increases gradually when lg(dF/dt), and it increases rapidly when lg(dF/dt). The tests prove that the newly-developed truncated cone is better than the conventional knife-wedge for measuring the dynamic fracture toughness of short-rod specimens of rocklike materials.