动静载下相似材料煤样破坏特征试验

Tests on failure characteristics of coal samples of similar materials under dynamic and static loads

为探究煤体在动静荷载下的破坏特征,本文以水泥、石膏为胶凝材料、全粒径煤粉灰为骨料,配比出相似材料煤样,利用万能试验机与霍普金森压杆试验装置开展动静态对比试验。结果表明:相似材料煤样的静、动态应力-应变曲线符合软煤的曲线特征,且具有动力增强特性;相似材料煤样的峰值应力主要受胶凝材料含量占比影响,其中水泥含量占比大的试样峰值应力最高,且在动载作用下,应力提升明显;相似材料煤样在动载作用下的破坏程度高于静载作用下的破坏,且主要受煤粉含量占比影响,其煤粉含量占比大的试样在动载作用下更加符合原煤粉碎的破坏特性。本文研究结果可为类似试验提供借鉴与参考。

In order to investigate the failure characteristics of coal bodies under dynamic and static loads, cement and gypsum are taken as cementitious materials and full-size coal ash as aggregate to proportion out coal samples of similar materials, and dynamic and static comparison tests are conducted by using universal testing machine and Hopkinson compression bar testing device.The results show that the static and dynamic stress-strain curves of similar material coal samples are in accordance with the curve characteristics of soft coal and have dynamic enhancement characteristics;the peak stress of similar material coal samples are mainly affected by the percentage of cementitious material content, among which the peak stress of specimens was large percentage of cement content, and the stress is elevated significantly under dynamic load;the failure of coal samples with similar materials under dynamic load is higher than that under static load, and it is mainly influenced by the proportion of coal dust content, and its specimens with a large proportion of coal dust content are more consistent with the failure characteristics of raw coal crushing under dynamic load.The results can provide references for similar tests.