装载机工作装置随机载荷统计特性分析

Statistical analysis on random load of working device of loader

装载机工作装置随机载荷的统计分析是工作装置载荷谱编制及结构疲劳分析的基础。文章实测了装载机工作装置在大石方、原生土、小石方和沙子4种物料工况下铲斗的受力载荷时间历程,采用统计方法对信号中的毛刺进行甄别与剔除,按照工况时间比例对载荷进行分段拼接,检验分段载荷的平稳性和各态历经性;利用数理统计的方法分析分段实测随机载荷的统计特性,采用峰谷抽取和雨流计数法统计载荷均值和幅值的频次,得到了均值频次和幅值频次分别服从正态分布和三参数威布尔分布的拟合分布数学模型,且载荷均值分布和幅值分布相互独立。随机载荷统计分析的方法和结果为装载机工作装置疲劳载荷谱编制以及可靠性台架试验提供了依据。

The statistical analysis of the random load is the basis for the preparation of the load spectrum and the structural fatigue analysis of the working device of loader.The bucket force load time history of the working device of loader was measured under four kinds of materials conditions including big rock,raw soil,small rock and sand.The statistical methods were used to identify and eliminate the singular value of the load signal.According to the proportion of working conditions,the load was segmented and spliced,and the stationary and ergodic properties of segmental load were tested.The mathematical statistics method was used to analyze the statistical characteristics of the random load,and the peak and valley extraction and rain flow counting method were used to count the frequency of the mean and amplitude values.The mean frequency and amplitude frequency obeyed normal distribution and three-parameter Weibull distribution respectively,and they were independent of each other.The statistical analysis method and result of the random load provide a reference for the preparation of the fatigue load spectrum and the reliability test of the working device of loader.