加载速率对砂岩破碎及能耗特征的影响

发布时间：2019-07-02 09:58

【摘要】：为了研究应力波加载速率对岩石破碎与能量利用效率的影响,利用杆件纵向撞击面局部变形的非线性模型设计了5种不同曲率半径的锤头,获得了非等入射能与等入射能条件下不同加载速率的入射应力波,并对红砂岩进行了冲击试验.结果表明:随着应力波加载速率的增大,砂岩试样破碎块度的分形维数呈近似线性增长关系.在加载速率相同的情况下,砂岩试样破碎块度的分形维数随入射能的增大而增大.随着入射应力波加载速率的增加,破碎能耗密度增大.在加载速率相同的情况下,入射能越大岩石破碎能耗密度越大.在非等入射能条件下,岩石破碎过程中的能量利用率随着入射能的增大呈明显的下降趋势.实际生产中最优的应力波形必须综合考虑破岩效果和能量利用率等因素.
[Abstract]:In order to study the effect of stress wave loading rate on rock breakage and energy utilization efficiency, five kinds of hammer heads with different curvature radii were designed by using the nonlinear model of local deformation of bar longitudinal impact surface, and the incident stress waves with different loading rates under the condition of unequal incident energy and equal incident energy were obtained, and the impact tests of red sandstone were carried out. The results show that with the increase of stress wave loading rate, the fractal dimension of broken block size of sandstone samples increases approximately linearly. When the loading rate is the same, the fractal dimension of sandstone fragmentation increases with the increase of incident energy. With the increase of loading rate of incident stress wave, the energy consumption density of crushing increases. When the loading rate is the same, the higher the incident energy, the greater the energy consumption density of rock breakage. Under the condition of non-equal incident energy, the energy utilization ratio in the process of rock breakage shows an obvious downward trend with the increase of incident energy. The optimal stress waveform in practical production must consider the rock breaking effect and energy utilization ratio.
【作者单位】：东北大学深部金属矿山安全开采教育部重点实验室;东北大学资源与土木工程学院;
【基金】：国家自然科学基金资助项目(51525402,51374049,51534003) 教育部科学技术研究重点资助项目(113019A) 中央高校基本科研业务费专项资金资助项目(N140105001,N140106002)
【分类号】：TU45

【相似文献】