轮式装载机液压缸载荷谱编制方法与时域信号重构

发布时间：2018-01-03 09:19

本文关键词：轮式装载机液压缸载荷谱编制方法与时域信号重构　出处：《吉林大学》2011年硕士论文　论文类型：学位论文

【摘要】：液压缸是轮式装载机液压传动系统的重要动力执行部件,装载机作业过程中的恶劣地面环境和复杂多变的铲掘载荷经常导致液压缸发生疲劳失效。载荷谱可以反映液压缸实际载荷情况,是液压缸疲劳分析的基础。本文结合国家自然科学基金资助项目(编号:50805065),根据轮式装载机的作业特点,研究了轮式装载机液压缸载荷的测试方案和数据预处理方法,提出了基于分段处理的液压缸载荷谱编制方法和基于马尔可夫理论的时域载荷重构方法;然后,应用所编制的载荷谱进行了缸筒的疲劳寿命预测。本文的研究工作可以为液压缸载荷谱的编制和时域信号的重构提供理论基础。论文主要内容和结论如下: 1、分析了液压缸的疲劳失效机理,描述了载荷谱的研究现状,进一步明确了编制液压缸载荷谱和进行时域信号重构的意义。 2、确定了测试方案并对样本载荷进行了预处理。从路面条件、司机的操作行为、装载机行进路线和物料的准备等方面对液压缸载荷的测试方案进行了规范。采用低通巴特沃斯的滤波方法对测试信号进行了滤波,并由幅值门限法进行了剔除奇异值。结合液压缸的工作特点,对测试载荷进行了分段处理,然后对每段载荷进行了统计分析和平稳性检验。 3、基于POT(峰值门限穿越法)外推方法,编制了液压缸全寿命载荷谱。根据POT理论,建立了广义帕累托分布(GDP)数学模型,并估计出分布参数。由雨流计数法统计出载荷的均值、幅值以及相应的频次。最后,由非参数外推将统计到的载荷频次外推到全寿命,完成了液压缸载荷谱的编制。 4、基于马尔可夫链理论,重构了液压缸时域载荷。基于马尔可夫链?蒙特卡罗方法对液压缸各作业段时域载荷和整体时域载荷进行了重构,模拟出实际工况中的载荷信号,实现了由测试载荷到模拟载荷的重现。 5、以动臂缸为例,进行了液压缸的有限元分析和疲劳寿命预测方法研究。首先,采用有限元软件分析了动臂缸筒体的强度和刚度。然后,基于实测的载荷数据和疲劳累积理论,计算了每一载荷幅值水平对液压缸产生的疲劳损伤。在有限元分析结果的基础上,利用本文编制的载荷谱预测出了动臂缸的疲劳寿命。
[Abstract]:The hydraulic cylinder is the important power executing part of the hydraulic transmission system of wheel loader . The severe ground environment and the complicated multi - variable shovel load in loader operation often result in the fatigue failure of the hydraulic cylinder . The load spectrum can reflect the actual load of the hydraulic cylinder and the method of time domain load reconstruction based on Markov theory . The research work of this paper can provide the theoretical basis for the compilation of hydraulic cylinder load spectrum and the reconstruction of time domain signal . The main contents and conclusions are as follows : 1 . The fatigue failure mechanism of the hydraulic cylinder is analyzed , the research status of the load spectrum is described , and the significance of the hydraulic cylinder load spectrum and the time domain signal reconstruction is further clarified . 2 . The test plan is determined and the sample load is pre - treated . The test scheme of hydraulic cylinder load is regulated in terms of pavement condition , driver ' s operating behavior , loading route of loader and preparation of material . The test signal is filtered by low - pass filter method . Combined with the working characteristics of hydraulic cylinder , the test load is subjected to segmentation treatment , and then the statistical analysis and stationarity test are carried out for each load . 3 . Based on POT ( peak threshold crossing method ) extrapolation method , the full life load spectrum of hydraulic cylinder is compiled . According to POT theory , the mathematical model of generalized Pareto distribution ( GDP ) is established , and the distribution parameters are estimated . The mean value , amplitude and frequency of the load are calculated by the rain flow counting method . Finally , the calculated load frequency is extrapolated to full life from non - parametric extrapolation , and the load spectrum of hydraulic cylinder is compiled . 4 . Based on Markov chain theory , the time domain load of hydraulic cylinder is reconstructed . Based on Markov chain ? Monte Carlo method , the time domain load and the whole time domain load of hydraulic cylinder are reconstructed , the load signal in the actual working condition is simulated , and the recurrence of the test load to the simulated load is realized . 5 . Taking the boom cylinder as an example , the finite element analysis and fatigue life prediction method of the hydraulic cylinder are studied . Firstly , the strength and rigidity of the boom cylinder are analyzed by finite element software . Based on the measured load data and the fatigue accumulation theory , the fatigue damage caused by the hydraulic cylinder is calculated . On the basis of the results of the finite element analysis , the fatigue life of the boom cylinder is predicted by the load spectrum .

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH243

【引证文献】