挖掘机破碎作业工作装置动态特性及疲劳分析

发布时间：2018-11-02 09:02

【摘要】：除了铲斗外，挖掘机的斗杆可以搭载各种作业装置，液压破碎锤就是其中一种。挖掘机破碎作业在实际生产中应用广泛，大大的提高了工作效率和劳动安全性。由于其作业特点，其工作装置在剧烈的冲击振动下往往出现共振、结构变形、关键位置疲劳磨损等破坏，相关的科研人员都进行了研究，但是都局限于动臂斗杆等单一构件上，，没有从整体上进行分析，本文从整体着手，通过对挖掘机破碎作业工作装置动态特性的研究，为其进行破碎锤与主机的频率匹配、结构优化以及延长工作装置的疲劳寿命提供参考和依据，主要工作如下： (1)首先介绍了挖掘机行业概况和挖掘机的各种作业装置，接着讨论了挖掘机工作装置的研究状况，并对挖掘机工作装置研究现状进行总结，针对这些问题提出了课题的目的意义和研究内容。 (2)随后分析了挖掘机装上破碎锤后在生产中优越性能以及出现的问题，建立其振动微分方程。根据参考机型建立工作装置的三维模型，再调节各组油缸的伸缩长度获得三种典型工况的三维模型。进行ANSYS Workbench与Pro/E无缝连接，将模型导入Workbench中，然后通过网格划分、边界条件设置，建立起三种工况的有限元模型。 (3)对工作装置进行无液体填充状态下的模态分析和固液耦合状态下的模态分析，得到三种工况工作装置的频率和振型，通过对结果进行分析对比，较为全面的了解了工作装置的模态，为破碎锤的频率匹配提供了参考。 (4)选择工作装置三处关键位置，对工作装置的三种工况进行谐响应分析，得出了工作装置关键位置的位移频率响应曲线，分析了结构关键部位的幅频特性，验证了工作装置承受共振作用、疲劳载荷以及其他持续动力学特性。 (5)在Workbench材料库中建立的工作装置的S-N曲线，对工作装置的三种典型工况进行了有限元疲劳分析，得到了最小疲劳寿命、及其发生的位置以及工作装置容易产生疲劳的区域，为工作装置的优化设计延长使用寿命提供了参考。
[Abstract]:In addition to bucket, excavator bucket pole can carry a variety of operating devices, hydraulic hammer is one of them. Excavator crushing is widely used in practical production and greatly improves working efficiency and labor safety. Because of its working characteristics, its working device often appears resonance, structural deformation, fatigue wear and other damage in the severe shock vibration. The relevant researchers have carried out research, but are confined to the single member such as the arm bucket rod, etc. There is no overall analysis, this paper starts from the whole, through the research of the dynamic characteristics of the excavator crushing work device, for which the frequency match between the hammer and the main engine is carried out. The main work is as follows: (1) the general situation of excavator industry and various kinds of excavator operating devices are introduced firstly. Then, the research status of excavator working device is discussed, and the research status of excavator working device is summarized, and the purpose significance and research content of the subject are put forward in view of these problems. (2) after analyzing the superior performance and problems in the production of excavator installed with crushing hammer, the vibration differential equation of excavator is established. According to the reference model, the three-dimensional model of the working device was established, and the three typical three dimensional model was obtained by adjusting the expansion length of each group of cylinders. The ANSYS Workbench and Pro/E are connected seamlessly and the model is imported into Workbench. Then the finite element model of three working conditions is established by meshing and setting up boundary conditions. (3) the mode analysis of the working device under the condition of no liquid filling and the mode analysis of the solid-liquid coupling state are carried out, and the frequency and mode shape of the working device under three working conditions are obtained, and the results are analyzed and compared. The mode of the working device is fully understood, which provides a reference for the frequency matching of the hammer. (4) selecting three key positions of the working device, analyzing the harmonic response of the three working conditions, obtaining the displacement frequency response curve of the key position of the working device, and analyzing the amplitude-frequency characteristic of the key position of the structure. The characteristics of resonance, fatigue load and other continuous dynamics of the working device are verified. (5) the S-N curve of the working device established in the Workbench material library is analyzed by finite element method under three typical working conditions, and the minimum fatigue life is obtained. The location of the device and the area where the working device is prone to fatigue provides a reference for the optimum design of the working device to prolong its service life.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU621

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