大理岩动态拉伸强度及弹性模量的SHPB实验研究

提出了获取脆性材料动态拉伸强度及弹性模量的实验步骤及相关记录数据的分析方法。利用直径为100mm的分离式Hopkinson压杆径向冲击巴西圆盘和平台巴西圆盘试样,测试了大理岩在高应变率加载下的动态力学性能。应力波加载下动态劈裂拉伸圆盘在试样中心产生了约45/s的拉伸应变率。分析了实验的有效性并考虑了试样两个端面应力波波形差异的影响以提高实验结果的精度。结果表明准静态下的公式可适用于动态劈裂拉伸实验;大理岩的动态拉伸强度及弹性模量比静态时有明显的增加。

Experimental Study for Dynamic Tensile Strength and Elastic Modulus of Marble using SHPB

An experimental procedure and accompanying method for analyzing recorded data for deriving dynamic tensile strength and elastic modulus of brittle material is presented. The split Hopkinson pressure bar with a diameter of 100mm and the Brazilian disc and the flattened Brazilian disc specimens subjected to diametral impact compression were used. Mechanical properties of the marble at high strain rate loading were tested. The dynamic split tension disc was subjected to a stress wave loading that produced tensile strain rate nearing 45/s at the center of specimen. The difference between the stress waves acting on the two flat ends of the flattened Brazilian disc specimen was considered to improve the accuracy of measurements; also the validity of experiments was analyzed. The results show that the formulas for quasi-static situation can be used in the corresponding dynamic split tension test, and that the dynamic tensile strength and elastic modulus of marble are substantially higher than the counterparts under static loading condition.