以具有突出倾向煤制备的型煤试件为研究对象,对其在循环载荷作用下的力学性质及不同载荷水平时的滞回曲线演化规律进行了分析。结果表明:型煤试件在循环载荷作用下的加、卸载曲线将形成滞回环,且从第2个循环后,开始出现次级滞回环;随着循环次数的增加,滞回曲线围成面积逐渐减小;循环载荷水平的选取与煤样的变形响应程度密切相关;滞回曲线的加卸载段分别可以用二次曲线进行表征,随着加卸载次数的增加,各拟合参数变化规律性明显,但与载荷水平变化规律性不强;加卸载阶段各对应拟合参数的符号均相反。
Briquette specimens made of outburst coal are taken as research objects,and both mechanical properties evolution under cyclic loading and law of hysteretic curve evolution under different loading level are studied.The results show that hysteretic loop is composed of load-unload curve when briquette specimens are studied under cyclic loading,and secondary hysteretic loop is produced from the second cycle.The area composed by hysteretic curve becomes smaller with the addition of cycle numbers.The relation between deformation response and loading level is very close.Load-unload curve of hysteretic curve is expressed by conic,and the change law of fitting parameters of conic is very regular with the addition of cycle numbers,but the regularity of the law with loading level isn't very obvious;the minis sign of fitting parameters of conic is opposite.