挖掘机液压系统压力载荷谱编制方法研究

发布时间：2018-01-02 10:20

本文关键词：挖掘机液压系统压力载荷谱编制方法研究　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：挖掘机恶劣的工作环境和繁重的工作任务对机器的质量和可靠性提出了很高的要求。以载荷谱为数据基础的整机及其关键部件的疲劳分析和可靠性试验是提升挖掘机质量与可靠性的重要手段,准确的载荷谱编制为分析和试验结果的合理性提供了保障。本文以国家科技支撑计划项目——“工程机械节能减排共性技术研究”(项目号:2015BAF07B01)为依托,选取挖掘机液压系统压力载荷为目标载荷,从载荷获取阶段起,安排三名司机进行载荷测试,分析三名司机操作下载荷特征的差异性,针对差异性载荷,提出了分位点外推方法,基于多准则决策技术进行分位点外推优化,完成了挖掘机液压系统压力载荷的外推与合成,并基于主泵泵体损伤等效原则给出了试验加载谱编制示例。本文主要的研究内容和分析结论总结如下:1.制定了挖掘机关键部件载荷测试方案。测试方案中,从测试系统建立、试验前准备和数据监测及整理等多方面进行了要求,并安排了三名司机进行操作。测试完成后,通过样本长度验证、平稳性和各态历经性检验确保测试数据满足要求;2.针对实测载荷,采用小波分形法进行降噪并通过关联维数判断降噪效果,采用最小二乘法进行了载荷的趋势项消除,并结合挖掘机分段作业的特点将完整作业循环进行了作业段划分。对目标载荷进行分析以验证多名司机操作下的载荷特性差异,采用了载荷特征值代替整体载荷的方法,基于显著性差异分析方法得到了不同司机之间载荷特性的差异性,验证了人为因素的影响,证明了使用分位点外推的必要性;3.基于分位点外推适用于处理差异性载荷的特点,将分位点外推应用于载荷谱编制之中。为了提高分位点外推的效率,首先对短期载荷进行里程外推。从基本步骤和算法角度深入分析了参数估计外推、极值外推和非参数外推三种常用的里程外推方法,总结了各种方法的关键点、优缺点和适用范围,编制了里程外推软件。考虑到液压系统压力载荷属于中小载荷循环,选择了非参数外推方法进行载荷的里程外推,为接下来的分位点外推做铺垫;4.介绍了分位点外推的基本原理和过程,为了解决分位点外推中分位点选择的主观性和盲目性,提出了分位点外推优化的思想。在确定先期分位点并进行外推的基础上,选择外推载荷谱中的关键特性作为准则,基于多准则决策技术计算各准则的综合权重,组成权重向量,用于优化载荷特性并决策出优化的分位点。以里程外推后的压力载荷为初始载荷,完成载荷的优化分位点外推,并验证了分位点外推的优化效果,为之后的试验加载谱编制提供数据;5.外推得到的长期载荷谱需要转化为程序加载谱加以应用,需要根据加载谱的应用需求确定转化路径。液压系统压力载荷应用广泛,本文以液压泵泵体为研究对象,以泵体疲劳损伤等效为原则,在完成载荷降维和材料属性值确定的基础上,通过试验条件和物理极限确定加载量值和频次,给出了试验加载谱的编制示例,并将加载谱用于泵体疲劳可靠性的台架试验中。
[Abstract]:The high requirements of excavator bad working environment and heavy tasks, the quality and reliability of the machine. The fatigue analysis and reliability test machine and its key components for data based on load spectrum is an important means to improve the quality and reliability of the excavator, guarantee the rationality of surely provide the Load Spectrum Compiling for analysis and testing results. This paper is supported by national science and technology projects "construction machinery energy saving common technology research" (project number: 2015BAF07B01) based on the selection of the excavator hydraulic system pressure load for the target load from the load acquisition phase, three drivers were load test, difference analysis of load characteristics of three drivers according to the difference of the operation load, put forward the quantile extrapolation method, multi criteria decision making technique of site optimization based on extrapolation, the excavator hydraulic Extrapolation and synthesis of pressure system pressure load, and based on the main pump body damage equivalent principle gives the test loading spectrum compiling examples. The research contents of this paper and the main conclusions are summarized as follows: 1. to develop the key components of the excavator load testing program. The testing project, built from the test system, test preparation and data monitoring and consolidation other aspects of the requirements, and arrange for three drivers to operate. The test is completed, the length of the sample verification, stationarity and ergodicity of the inspection to ensure that test data to meet the requirements; 2. for the actual load, noise reduction and noise reduction effect by judging correlation dimension using wavelet fractal method, the trend for load to eliminate the use of least squares method, combined with the characteristics of excavator sectional operation will complete the work cycle operation segment. The target load is analyzed to verify more than our Different load characteristics under the machine operation, the load characteristic value instead of the method of whole load, significant difference analysis method of difference between the different load characteristics of the driver has been verified based on the influence of human factors, proved the necessity to use quantile extrapolation based on Quantile extrapolation; 3. characteristics of suitable for processing the difference the load will be used for compiling the load spectrum extrapolation site. In order to improve the efficiency of quantile extrapolation, first mileage extrapolation of short-term load. From the basic steps and algorithm in-depth analysis of the parameter estimation, extreme extrapolation and non parameter extrapolation of three commonly used distance extrapolation method, summarizes the key points of various methods the advantages and disadvantages of mileage, extrapolation software. Considering the hydraulic system pressure loads are small and medium load cycle, choose a non parametric method for load extrapolation The mileage of extrapolation, pave the way for the next 4. quantile extrapolation; introduces the basic principle and process of quantile extrapolation, in order to solve the choice of quantile quantile in the extrapolation of subjectivity and blindness, proposed site optimization theory based on extrapolation. Determining pre quantile and for extrapolation on the choice of the key the characteristics of load spectrum extrapolation as the criterion, the comprehensive weight of multi criteria decision making technique to calculate each criterion based on the composition of the weight vector, is used to optimize the load characteristics and decision quantile optimization. To load the initial mileage extrapolation load, make the load optimization quantile extrapolation, and verify the optimization effect of quantile the extrapolation of the test for the long-term load spectrum compiling data; 5. extrapolated spectrum needs to be applied to the program load spectrum, according to the application needs to determine the loading spectrum The path. The hydraulic system pressure load is used widely, based on the hydraulic pump as the research object, using the pump body fatigue damage equivalent principle, based on the load to determine the dimensionality reduction and material attribute value, determine the magnitude and frequency of the loading test conditions and physical limits, given the sample preparation test loading spectrum. The bench test load spectrum for fatigue reliability of the pump.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU621

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