机械振动下煤岩体力学特性及能量耗散实验研究

发布时间：2018-05-24 05:42

本文选题：相似材料 + 机械振动　；参考：《西安科技大学》2017年硕士论文

【摘要】：在“固-气”耦合相似材料的研究成果和最新进展的基础上,开展机械振动影响下物理相似模拟实验,深入开展煤岩体受振时力学特性的变化规律,研究振动环境下煤岩破坏过程中能量演化机制,从能量转化、能量演化及受振前后能量差的细观特征等三个方面研究了相似材料在振-压耦合过程中的能量行为,在振动模拟方面为煤与瓦斯安全共采体系提供理论基础。运用正交实验设计法及综合评分法对振动实验所需相似材料的配比进行实验设计,通过不同材料特性对比分析进行原材料选择。应用材料力学、断裂力学、振动力学及热力学等基本理论与方法,构建振动频率与相似材料弹性模量、抗压强度的关系模型,研究了机械振动后相似材料力学参数的变化规律。基于自行组装的煤岩单轴约束下振动实验系统,对5组不同配比的相似材料试件开展力学性质、弹性应变密度能及耗散密度能测试实验,总结出机械振动频率对试件力学参数、弹性应变密度能及耗散密度能的影响。通过建立的相似材料力学参数与振动频率关系模型,计算得到不同振动频率下相似材料试件的抗压强度及弹性模量,与实验结果较为吻合。单轴以及振-压两种不同的加载模式下,相似材料的能量演化规律均经历能量输入、能量积聚和能量耗散3个阶段。研究单向受载及振动下相似材料的能量演化规律,得到单向加载与振动耦合作用下相似材料的力学特征,分析了随频率演化的能量密度值、能量差及能量差比率的发展规律。能量密度值、能量差及能量差比率这三个参数可表征不同频率下相似材料力学特征的发展规律,并通过大量实验数据及关系模型论证分析方法的合理性。
[Abstract]:On the basis of the research results and recent progress of the "solid-gas" coupling similar materials, the physical similarity simulation experiment under the influence of mechanical vibration is carried out, and the variation law of mechanical properties of coal and rock mass under vibration is deeply carried out. The mechanism of energy evolution in the process of coal and rock failure under vibration environment is studied. The energy behavior of similar materials in the process of vibration-pressure coupling is studied from three aspects: energy transformation, energy evolution and mesoscopic characteristics of energy difference before and after vibration. In the aspect of vibration simulation, it provides a theoretical basis for coal and gas safe mining system. The orthogonal experimental design method and comprehensive scoring method were used to design the proportion of the similar materials needed in vibration experiment. The raw materials were selected by comparing and analyzing the characteristics of different materials. Based on the basic theories and methods of material mechanics, fracture mechanics, vibration dynamics and thermodynamics, the relationship between vibration frequency and elastic modulus and compressive strength of similar materials is established, and the variation law of mechanical parameters of similar materials after mechanical vibration is studied. Based on the self-assembled uniaxial vibration test system of coal and rock, the mechanical properties, elastic strain density energy and dissipation density energy of five groups of similar material specimens with different ratios were tested, and the mechanical parameters of mechanical vibration frequency to the specimen were summarized. The influence of elastic strain density energy and dissipation density energy. The compressive strength and elastic modulus of the specimens of similar materials under different vibration frequencies are calculated by the model of the relationship between mechanical parameters of similar materials and vibration frequency, which is in good agreement with the experimental results. Under the uniaxial and vibration-pressure loading modes, the energy evolution of the similar materials goes through three stages: energy input, energy accumulation and energy dissipation. The law of energy evolution of similar materials under unidirectional loading and vibration is studied. The mechanical characteristics of similar materials under unidirectional loading and vibration coupling are obtained. The development laws of energy density, energy difference and ratio of energy difference with frequency evolution are analyzed. The three parameters of energy density, energy difference and energy difference ratio can characterize the development law of similar material mechanics characteristics at different frequencies, and the rationality of the analytical method is demonstrated by a large number of experimental data and relational models.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD313

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