摘要
振动筛在制造、安装等环节中不可避免地存在随机因素.本文基于随机结构模型对直线振动筛结构进行随机模态分析,给出了模态频率变异性的统计描述方法,研究了随机结构参数(橡胶弹簧弹性模量及密度、钢材弹性模量及密度)对振动筛模态频率的影响规律.结果表明:一阶矩意义下,橡胶弹簧弹性模量随机时对结构前三阶模态频率均值影响大,钢材密度随机时对结构高阶模态频率均值影响大;二阶矩意义下,橡胶弹簧弹性模量随机引起的前三阶模态频率相对其均值的动态偏离大,钢材弹性模量及密度随机引起的高阶模态频率相对其均值的动态偏离大;橡胶弹簧密度随机时对模态频率影响很小.对模态频率变异的灵敏参数分析得出:橡胶弹簧弹性模量随机时对低阶频率(前三阶)的相对均差系数及变异系数影响最灵敏.钢材弹性模量随机对高阶频率变异系数影响最灵敏,钢材密度随机对高阶频率的相对均差系数影响最为灵敏.
Stochastic factors inevitably exist in the process of vibrating screen manufacture and installation. Based on stochastic structure model, the stochastic modal analysis was made, the statistical description of modal frequency variability was given, and the effects of stochastic parameters（ elastic modulus, density of the rubber spring or steel）to vibrating screen modal frequencies were discussed. The results showed that, in a sense of first-moment, stochastic rubber spring elastic modulus had important influence on the mean value of the first three frequencies for vibrating screen, stochastic steel density had a greater effect on mean value of high-order frequencies. In a sense of second-moment, the mean value dynamic deviation of the first three frequencies was larger which caused by stochastic variation coefficient of rubber spring elastic modulus. The mean value dynamic deviation of high-order frequencies was larger, caused by stochastic variation coefficients of steel elastic modulus or density. Stochastic rubber spring density had little effect on the modal frequencies. Analyzing sensitive parameters to modal frequency variation coefficient, it drew a conclusion that the variation coefficient of rubber spring elastic modulus was the most sensitive parameter to relative mean value deviation coefficient and variation coefficient of the lower orders frequencies, the variation coefficient of steel elastic modulus was the most sensitive parameter to variation coefficient of the high-order frequencies, and the variation coefficient of steel density was the most sensitive parameter to relative mean value deviation coefficient of the high-order frequencies.
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2012年第4期632-641,共10页
Journal of Basic Science and Engineering
基金
国家"十一五"科技支撑计划课题项目(2006BAA01B05)
中国煤炭工业科技计划项目(MTKJ2009-279)
关键词
直线振动筛
随机分析
模态频率
灵敏参数
弹性模量
密度
linear vibrating screen
stochastic analysis
modal frequency
sensitive parameter
elastic modulus
density
