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利用自制落锤式煤岩冲击加载试验装置,配合超声波检测设备,对型煤在不同冲击荷载作用下内部微结构及表面新生裂隙的发展演化规律进行系统的试验研究,并分析冲击荷载对型煤内部微结构演化产生影响的机制。结果表明:型煤内部微结构演化与冲击荷载作用次数、单次冲击能量大小、冲击能量施加顺序、冲击能量的累计效果等因素有关;型煤内部微结构的扩展和表面新生裂隙的出现、发展均表现出明显的各向异性,沿冲击荷载方向上比垂直冲击方向上变化显著;相同的冲击荷载作用下,型煤内部微结构总数量随着冲击次数的增加呈现出“高速增加→平缓发展→急速增加”的趋势;不同冲击荷载作用时,随着单次冲击能量的增加,型煤内部微结构总数量呈指数函数关系增大,型煤表面新生裂隙局部化分布特点更为显著;型煤内部微结构演化对冲击能量由大到小进行施加更为敏感;冲击荷载对型煤内部微结构影响的累计效果也呈非线性规律,表现为先增大后减小趋势,其不可简单等效为冲击能量的增加;型煤对冲击能量的吸收率随着单次冲击能量的增加呈减小趋势,表现为大于一定值的较小冲击能量的累计效果要大于等值单次较大冲击能量对型煤造成的影响。
The self-made drop-weight coal-rock impact loading test device was used in combination with the ultrasonic testing equipment to systematically test and study the evolution and evolution of the bauxite under the impact of different impact loads and on the surface fissures. The influence of impact load on briquette Mechanisms that influence the evolution of internal microstructures. The results show that the microstructure evolution of briquette is related to the number of impact loads, the magnitude of single impact energy, the order of impact energy application, the cumulative effect of impact energy and other factors. The internal microstructure evolution of briquette and the appearance and development of surface fissures All showed obvious anisotropy, which showed significant changes in the direction of impact load compared with the direction of vertical impact. Under the same impact load, the total number of microstructures in briquette showed “rapid increase → gentle” with the increase of impact times Development → rapid increase "trend; with different impact loads, with the increase of single impact energy, the total amount of microstructure in briquette increases exponentially, and the localized distribution of fresh fissures on briquette surface is more significant ; The internal microstructure evolution of briquette is more sensitive to impact energy applied from large to small; the cumulative effect of impact load on the internal microstructure of briquette also shows a non-linear rule, which first increases and then decreases, Simple equivalent is the increase of impact energy. The absorptivity of briquette to impact energy decreases with the increase of single impact energy, The cumulative effect of setting a smaller impact energy is greater than the effect of a single larger impact energy on briquette.