加载速率影响抗拉强度的机理及其数值验证

发布时间：2018-04-04 01:38

本文选题：推进速度　切入点：加载速率　出处：《煤炭学报》2017年S1期

【摘要】：井下工作面由于推进速度的不同导致覆岩对顶板的加载速率不同,使得顶板岩层表现出不同的抗拉强度,因此加载速率影响岩石抗拉强度的机理对于掌握不同推进速度下的采场矿压显现规律至关重要。通过对覆岩运移规律的分析首先定义了2种加载速率,即外力加载速率和位移加载速率;然后通过室内岩石力学实验掌握了加载速率越大岩石抗拉强度越大的规律;接着使用弹性动力学方法和分子尺度的功能原理分别解释了外力加载速率和位移加载速率影响抗拉强度的作用机理;最后,通过ANSYS/LS-DYNA对不同加载速率下的巴西劈裂实验进行了瞬态动力学分析,进一步验证了加载速率对抗拉强度的作用效果。结果表明,外力加载速率不同时系统产生的惯性力不同,位移加载速率不同时,破坏时物体的动能也不同,最终使得不同加载速率下物体表现出不同的抗拉强度。
[Abstract]:Underground working face advancing speed due to different loading rate of overlying rock on the roof, the roof strata exhibit different tensile strength, so the loading rate effect mechanism of rock tensile strength for the grasp of different speed under the mining pressure behavior is very important. Through the analysis of the movement law of overburden are first defined 2 kinds of loading rate, the loading rate and displacement loading rate; and then through the indoor rock mechanics experiment has the greater loading rate of rock tensile strength greater of the function principle; then use the elastic dynamics method and molecular scale respectively explain the loading rate and displacement loading rate effects of tensile strength; finally. The transient dynamic analysis of crack through the experiment under different loading rates of Brazil ANSYS/LS-DYNA split further verified the loading rate. The results show that the inertial force generated by the system is different from that of the external force loading rate, and the kinetic energy of the object is different when the displacement loading rate is different. Finally, the object exhibits different tensile strength under different loading rates.

【作者单位】：中国矿业大学(北京)资源与安全工程学院;放顶煤开采煤炭行业工程研究中心;
【基金】：国家重点基础研究发展计划(973)资助项目(2013CB227903) 国家重点研发计划资助项目(2016YFC0801401)
【分类号】：TD315

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