岩石在不同应力幅值下受低频循环扰动的力学特性试验

发布时间：2018-02-12 19:57

  本文关键词： 循环扰动 高应力 应力幅值 损伤模型　出处：《煤炭学报》2017年09期 　论文类型：期刊论文

【摘要】：设计3种不同类型的岩石在不同应力幅值下的循环扰动试验。试验结果表明:当扰动应力幅值较小时,岩石在循环加载下出现弹性模量强化效应,不同类型的岩石弹性模量强化程度不同;循环动力扰动加载试验存在应力上限门槛值,只有大于应力上限门槛值,试样才会发生破坏;扰动应力幅值对岩石的破坏影响显著,在高应力幅值下,循环次数迅速减少;在低应力幅值下,试件破坏形态为剪切破坏,在高应力幅值下,破坏形态复杂,出现板裂化破坏和碎块弹射。建立了循环扰动作用下的应变损伤模型,通过分析不同应力幅值下损伤变量的变化规律,得出如下结论:岩石损伤可划分为迅速增长阶段、平稳发展阶段、快速增大阶段,且随着扰动应力幅值的增加,平稳发展阶段的循环数显著减少;当应力幅值提高,损伤变量变化率显著提高,应变迅速增加,岩石破坏。
[Abstract]:The cyclic disturbance tests of three different types of rock under different stress amplitudes are designed. The experimental results show that when the amplitude of disturbance stress is small, the elastic modulus strengthening effect appears under cyclic loading. Different types of rock have different strengthening degree of elastic modulus, the stress upper limit threshold exists in cyclic dynamic disturbance loading test, only when the stress threshold value is larger than the upper limit value, the specimen will be destroyed, and the disturbance stress amplitude has a significant effect on rock failure. Under the high stress amplitude, the number of cycles decreases rapidly, the failure mode of the specimen is shear failure at low stress amplitude, and the failure form is complex under the high stress amplitude. The strain damage model under cyclic disturbance is established. By analyzing the variation of damage variables under different stress amplitudes, it is concluded that rock damage can be divided into rapid growth stages. The cycle number of the steady development stage decreases significantly with the increase of the amplitude of disturbance stress, and the rate of change of damage variable increases significantly, the strain increases rapidly, and the rock failure occurs when the stress amplitude increases.
【作者单位】： 北京科技大学土木与资源工程学院;金属矿山高效开采与安全教育部重点实验室;北京市信息服务工程重点实验室;中南大学高等研究中心;
【基金】：中国矿业大学深部岩土力学与地下工程国家重点实验室开放基金资助项目(SKLGDUEK1418) 湖南省自然科学基金资助项目(2017JJ3390)
【分类号】：TD315
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本文编号：1506433