液压破碎锤疲劳寿命分析与仿真研究

发布时间：2018-07-17 02:06

【摘要】：液压破碎锤是特种车辆上的作业工具，其通过液压驱动活塞撞击钎杆将岩石等物体破碎。随着基础设施建设和煤矿能源的大力发展，液压破碎锤被广泛地应用于各种施工现场。因此，完善液压破碎锤的设计方案，使设计成本降低、可靠性增强是提高产品竞争力的主要研究方向。本文以某型号液压破碎锤为研究对象，从以下几个方面展开了研究。首先，在介绍液压破碎锤工作原理的基础上，建立其活塞和换向阀阀芯的运动微分方程，，并利用液压系统仿真软件DSHplus建立其液压系统的仿真模型。从仿真的结果中获得液压破碎锤工作参数的变化趋势。建立液压破碎锤的三维模型，采用多体动力学仿真软件RecurDyn和Matlab/Simulink对破碎锤进行多体动力学分析并与试验结果进行对比，论证多体动力学模型的正确性并从中获取液压破碎锤有限元仿真所需的边界条件。其次，对液压破碎锤的几何模型进行简化，利用前处理软件HyperMesh建立液压破碎锤的有限元模型。在此基础上，利用多体动力学分析的结果作为有限元分析的边界条件，利用LS-Dyna对模型进行求解，并分析计算的结果。结果表明液压破碎锤的钎杆在工作过程中所受的应力最大，接近材料的屈服极限，其他部件所受的应力均低于材料的屈服极限。有限元分析结果为液压破碎锤的疲劳寿命分析提供了各个部件的应力、应变的时间历程。接着，介绍了金属材料的疲劳破坏特征、疲劳裂纹的产生过程、疲劳寿命的定义和疲劳损伤的累积方法。采用雨流计数法作为载荷历程的统计方法，Palmgren一Miner准则为疲劳损伤的累积方法，以Femap为软件的开发载体，利用C#语言调用Femap的API开发出一套疲劳分析软件。最后，在获得有限元计算结果的基础上正确选择疲劳算法，对液压破碎锤的各个部件进行疲劳寿命的定量分析。把计算结果与知名的疲劳分析软件fe-safe的计算结果做对比，误差在8%以内，验证了分析结果的准确性。此外，计算的结果也与工程实际情况较为符合。表明所提供的液压破碎锤疲劳寿命分析流程和分析结果都具有一定的可靠性。在工程机械的研发朝着以计算机仿真为主导趋势的今天。论文中提出的以计算机仿真技术为基础的液压破碎锤疲劳寿命的分析流程与结果对液压破碎锤的开发和优化具有一定的参考意义。
[Abstract]:Hydraulic crushing hammer is a working tool for special vehicles. It breaks rock and other objects by hydraulic driving piston hitting drill rod. With the development of infrastructure and coal mine energy, hydraulic hammer is widely used in various construction sites. Therefore, improving the design scheme of hydraulic hammer, reducing the design cost and enhancing the reliability are the main research directions to improve the competitiveness of the products. In this paper, a certain type of hydraulic hammer as the research object, from the following aspects of the research. Firstly, on the basis of introducing the working principle of hydraulic crushing hammer, the differential equations of motion of piston and valve core are established, and the simulation model of hydraulic system is established by using the hydraulic system simulation software DSHplus. The changing trend of working parameters of hydraulic hammer is obtained from the simulation results. The three-dimensional model of hydraulic hammer was established. The multi-body dynamics simulation software RecurDyn and Matlab / P Simulink were used to analyze the multi-body dynamics of the hammer and the results were compared with the experimental results. The validity of multi-body dynamic model is demonstrated and the boundary conditions for finite element simulation of hydraulic hammer are obtained. Secondly, the geometric model of hydraulic hammer is simplified, and the finite element model of hydraulic hammer is established by preprocessing software HyperMesh. On this basis, the results of multi-body dynamics analysis are used as the boundary conditions of finite element analysis, and the model is solved by LS-Dyna, and the results are analyzed. The results show that the stress of the drill rod of the hydraulic hammer is the largest in the working process, close to the yield limit of the material, and the stress of the other parts is lower than the yield limit of the material. The results of finite element analysis provide the time history of stress and strain for the fatigue life analysis of hydraulic hammer. Then, the fatigue failure characteristics of metal materials, the process of fatigue cracks, the definition of fatigue life and the cumulative method of fatigue damage are introduced. Using rain flow counting method as the statistical method of load history, Palmgren-Miner criterion is used as the cumulative method of fatigue damage, and Femap is used as the software development carrier, and a set of fatigue analysis software is developed by using C # language to call Femap API. Finally, on the basis of obtaining the results of finite element calculation, the fatigue algorithm is correctly selected to quantitatively analyze the fatigue life of every component of the hydraulic hammer. The calculation results are compared with those of the well-known fatigue analysis software fe-safe, and the error is less than 8%, which verifies the accuracy of the analysis results. In addition, the calculated results are in good agreement with the actual situation of the project. It is shown that the fatigue life analysis flow and the analysis results provided by the hydraulic hammer have certain reliability. In the construction machinery research and development towards the computer simulation as the dominant trend today. The analysis flow and result of the fatigue life of hydraulic hammer based on computer simulation technology presented in this paper have certain reference significance for the development and optimization of hydraulic hammer.
【学位授予单位】：上海工程技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH137;U469.6

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