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煤岩弹性变形能的表征物理模型及实测方法

Physical model and measurement method for elastic deformation energy characterization of coal and rock

  • 摘要: 现有冲击倾向性测试结果常表现出与冲击地压事故互为不充分不必要条件的关系,对于工程的参考价值有待进一步提高。为此,从冲击倾向性描述弹性能的本质出发,构建了从功能上能够还原弹性能积聚与释放的统计损伤物理模型,从基本物理行为的角度对应力-应变曲线的升降趋势,以及加载过程中能量的积聚与耗散进行了研究。结果表明:外载做功和能量释放贯穿加载全过程,目前以应力-应变曲线峰前、峰后段的相关特征分别描述弹性能积聚和耗散的方式能够简化计算,但未能反应真实的力学行为,基于物理模型进一步指出,试件的变形势能增量ΔWti本质上是当前时刻试件中仍具承载能力结构新增的变形能ΔW′ti与该时刻破断的承载结构所释放变形能ΔW″ti之差,而ΔW′ti在描述弹性能方面更具合理性,并给出了该指标基于荷载-时间曲线和声发射的实测计算路径,为获得更为准确的弹性能描述做出了有益探索。

     

    Abstract: The current test results of coal seam bursting tendency and coal bump accident are mutually inadequate and unnecessary conditions. The test results of bursting tendency need to be further improved for the reference value of coal mining. From the essence of bursting tendency to describe elastic energy, this study establishes a statistical damage physical model that can restore the accumulation and release of elastic energy. The rising and falling trend of stress-strain curve, the energy accumulation and dissipation during loading are studied from the perspective of basic physical behavior . The results show that external load work and energy release run through the entire loading process, and the current ways of describing the accumulation and dissipation of elastic energy with the characteristics of the pre-peak and post-peak sections has advantages in simplifying the calculation, but fail to reflect the true underlying physical logic. Based on the physical model, it is pointed out that the increase in deformation potential energy of the specimen ΔWti is essentially the difference between the new deformation energy ΔW′ti in the structure with the load-bearing capacity and the deformation energy ΔW″ ti released by breaking the load-bearing structure at that moment. ΔW′ti is more reasonable in describing the elastic performance. The calculation method of the index based on the load-time curve and the acoustic emission information is derived, which is a useful exploration for obtaining more accurate elastic energy.

     

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