刨煤机多体动力学分析及疲劳寿命预测

发布时间：2018-05-26 09:55

本文选题：刨煤机 + 疲劳寿命　；参考：《辽宁工程技术大学》2015年硕士论文

【摘要】：我国薄煤层煤炭资源丰富,随着煤炭资源的日益减少,薄煤层工作面的开采已成为提高煤炭生产产量的一个方向,而刨煤机作为开采薄煤层煤炭的重要设备,也逐渐被煤机生产单位所重视,纷纷加大对刨煤机的研究工作,但由于国内对刨煤机的研究起步较晚,特别对刨煤机整机的力学性能研究的相对较少,导致刨煤机的可靠性和寿命相对较弱,针对上述问题,本文主要完成以下工作：首先采用单自由度振动理论,忽略刨头前、后的链条质量等因素的影响,将刨头视为集中质量块,建立了含有刨煤机前、后驱动链轮多边形效应的单自由度动力学模型；再以单自由度模型为基础,综合考虑刨链的质量、刨链的预紧力及前后驱动系统振动等诸多因素,建立了刨煤机多自由度动力学模型。以刨煤机工况下的载荷为负载激励,采用龙格库塔法对刨煤机整机动力学模型进行求解,得到了刨链张力及刨头振动的时间历程曲线,并对提取了刨链张力及刨头振动的时域特征值；采用对比方法,得到了工况下刨头前、后侧链条张力的变化特性,并分析了不同预紧力和不同刨削深度对刨链张力的影响。采用有限元仿真技术,建立了刨链的静力学模型,研究了最大工作载荷下,刨链的应力、应变分布状态；利用ANSYS workbench有限元软件对刨链进行模态分析,研究其固有频率,得到十阶固有频率及其振型。同时对刨煤机链轮在随机载荷作用下的疲劳损伤进行了分析与研究,得到了刨煤机链轮槽处的最大应力值为1×106 Pa。最后运用雨流计数法与Miner疲劳累计损伤理论相结合的方法对刨煤机进行寿命预测。得到了刨煤机在特定的工作环境下的寿命时间。所得结论为改进和设计刨煤机提供了理论基础,为刨煤机在不同的工况下动态特性提供理论依据。
[Abstract]:China is rich in coal resources in thin coal seams. With the decreasing of coal resources, the mining of thin coal face has become a direction to improve the production of coal, and the planer is an important equipment for mining coal in thin coal seam. It has been paid more and more attention to by the coal machine production units, and has increased the research work of the coal plough one after another. However, due to the late start of the research on the coal plough in our country, especially the research on the mechanical properties of the whole coal plough machine is relatively less. The reliability and life of the planer are relatively weak. In view of the above problems, this paper mainly completes the following work: firstly, the single degree of freedom vibration theory is adopted, and the influence of factors such as the quality of the chain in front and back of the planer is ignored. The planer head is regarded as a lumped mass block, and a single degree of freedom dynamic model with polygon effect of the chain wheel driven before and after the coal plough is established, and the quality of the planing chain is considered synthetically on the basis of the single degree of freedom model. The multi-degree-of-freedom dynamic model of the coal plough is established by many factors, such as the pretightening force and the vibration of the front and rear drive system. Taking the load under the working condition of the plough as the load excitation, the dynamic model of the whole planer is solved by the Runge-Kutta method, and the time history curves of the tension of the planer and the vibration of the planer head are obtained. The time domain eigenvalues of the tension of the planer and the vibration of the planer are extracted, the variation characteristics of the chain tension at the front and rear side of the planer are obtained by using the contrast method, and the effects of different pretightening forces and different planing depths on the tension of the planer are analyzed. Using finite element simulation technology, the static model of the planer chain is established, and the stress and strain distribution state of the planer chain under the maximum working load is studied, and the modal analysis of the planer chain is carried out by using ANSYS workbench finite element software, and the natural frequency of the planer chain is studied. The tenth order natural frequency and its mode shape are obtained. At the same time, the fatigue damage of the coal plough sprocket under random load is analyzed and studied. The maximum stress at the sprocket of the plough is 1 脳 10 ~ 6 Pa. Finally, the method of rain flow counting and Miner fatigue cumulative damage theory is used to predict the life of coal plough. The life time of the coal plough in a specific working environment is obtained. The conclusion provides a theoretical basis for improving and designing the coal plough and provides a theoretical basis for the dynamic characteristics of the plough under different working conditions.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD421.62

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