两向加卸载含瓦斯煤变形破裂数值模拟研究

发布时间：2018-03-17 09:09

本文选题：轴向加载-横向卸载　切入点：含瓦斯煤　出处：《煤矿安全》2017年12期 　论文类型：期刊论文

【摘要】：为了模拟煤矿工作面前方应力变化时含瓦斯煤体的力学特性,应用RFPA~(2D)-Flow软件模拟研究了轴向加载-横向卸载作用下含瓦斯煤的变形破裂规律,讨论了初始围压、轴压和卸载速率效应对试样变形破坏的影响。研究结果表明:在加载和卸载方向,轴向应力和横向应力初期都呈线性增加,当达到极限强度后煤体的变形破裂导致急剧的应力降,直至煤样失去承载能力时基本保持恒定。初始围压、轴压越大,卸载速率越小,煤体的极限抗压、拉强度及其对应的轴向、横向应变越大;峰值强度及应变与初始围压、轴压呈明显的线性相关性,而与卸载速率表现出阶梯状,随着卸载速率的增加极限强度及应变减小速率逐渐降低。
[Abstract]:In order to simulate the mechanical characteristics of gas-bearing coal under the change of stress in the front of coal face, the deformation and fracture law of gas-bearing coal under axial loading and transverse unloading is simulated by using RFPA~(2D)-Flow software, and the initial confining pressure is discussed. The effect of axial compression and unloading rate on the deformation and failure of specimens. The results show that the axial stress and transverse stress increase linearly in the direction of loading and unloading. When the ultimate strength is reached, the deformation and rupture of the coal body lead to sharp stress drop, until the coal sample loses its bearing capacity, the initial confining pressure, the greater the axial pressure, the smaller the unloading rate, the lower the ultimate compressive strength of the coal body, the higher the initial confining pressure, the greater the axial pressure, and the smaller the unloading rate. The tensile strength and its corresponding axial direction, the transverse strain is larger, the peak strength and strain have obvious linear correlation with the initial confining pressure and axial pressure, while the axial pressure has a ladder shape with the unloading rate. With the increase of unloading rate, the limit strength and strain decrease rate gradually decrease.
【作者单位】：中国矿业大学安全工程学院;青岛理工大学安全科学与工程系;
【基金】：国家自然科学基金资助项目(51504140) 江苏省普通高校学术学位研究生科研创新计划资助项目(KYLX16-0572) 中国矿业大学大学生创新基金资助项目(DC201609)
【分类号】：TD712

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