改善高韧性顶煤爆破效果的数值模拟

针对高韧性煤的弹性模量小且抗拉强度大,冒放性较差的问题,通过有限元软件LS-DYNA2D,对封闭煤体中爆炸过程进行了数值模拟,模拟结果表明顶煤的炮孔孔径的合理选取是改善高韧性冒放性较差的关键,煤体中质点压应力随着径向半径增大与时间的推移迅速减小的规律。离爆心近处,质点的压应力很大;离爆心远处,质点的压应力较小。得出了采用大药卷是改善高韧性冒放性较差主要途径。从而为改善高韧性冒放性较差的爆破参数优化提供了了一种切实可行的研究方法。

Power ultrasound-induced heating mechanism of gas in coal seam

There are some caving difficulties in top-caving coals due to their low elastic mould,high toughness and high tensile strength. Using finite element software LS-DYNA2D,the blasting process is simulated in an enclosed coal body. The result shows that the rational determination of blast hole spacing is the key to improvement of the caving and drawing capability of high toughness top-coals. Also,the stress in coal body reduces rapidly with the increase of radial radius and time passing. The stress is very high...