循环加载下冲击倾向性煤能量耗散与损伤演化研究

发布时间：2018-03-02 17:40

本文选题：强冲击倾向煤　切入点：多级循环加载　出处：《煤炭科学技术》2017年02期 　论文类型：期刊论文

【摘要】：为研究强冲击倾向性煤在多级循环加载条件下的能量耗散特征及损伤演化过程,在实验室开展了陕西某矿煤样的多级循环加载试验,试验研究结果表明:在多级应力循环下煤样的耗散能先迅速降低,后缓慢增加,当循环上限应力达到63%破坏载荷时,耗散能开始急剧增加;而能量耗散率先迅速降低,后逐渐稳定;煤样加卸载阶段弹性模量均有增大趋势,加载阶段弹性模量先迅速增大,后缓慢增加,而卸载阶段弹性模量变化较为平稳。采用累积耗散能定义循环加载中试件的损伤变量,并建立煤样损伤演化方程,通过试验和数值计算测定各个参数。理论和试验研究表明,基于能量耗散分析建立的冲击倾向性煤损伤演化方程能够较好反映煤样的损伤演化过程。
[Abstract]:In order to study the energy dissipation characteristics and damage evolution process of highly percussive coal under multistage cyclic loading, a multistage cyclic loading test of coal samples from a certain mine in Shaanxi Province was carried out in the laboratory. The experimental results show that the dissipation energy of coal samples decreases rapidly first and then increases slowly under multistage stress cycling. When the upper limit stress of the cycle reaches 63% failure load, the dissipation energy begins to increase sharply, while the energy dissipation decreases rapidly. After loading, the elastic modulus of the coal samples increased gradually, and the elastic modulus of the coal samples increased rapidly at the loading stage, and then slowly increased at the loading stage. However, the change of elastic modulus at unloading stage is relatively stable. The damage variable of the specimen under cyclic loading is defined by accumulative dissipative energy, and the damage evolution equation of coal sample is established. The parameters are measured by experiment and numerical calculation. The theoretical and experimental results show that, The damage evolution equation based on energy dissipation analysis can better reflect the damage evolution process of coal samples.
【作者单位】：煤炭科学研究总院开采设计研究分院;煤炭科学技术研究院有限公司安全分院;煤炭资源高效开采与洁净利用国家重点实验室(煤炭科学技术研究总院);
【基金】：国家自然科学基金资助项目(51574150)
【分类号】：TD324

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