基于应变模态的振动筛横梁损伤诊断及疲劳剩余寿命预测研究
发布时间：2019-04-12 19:50
【摘要】：基于模态理论对振动筛横梁进行了位移和应变模态分析,结果表明横梁损伤前、后同阶模态频率的相对偏差较小,位移模态振型亦无明显突变,而应变模态振型在横梁损伤后产生了突变峰值。据此构建了应变模态变化率作为横梁损伤诊断指标,分析结果表明应变模态变化率随横梁损伤程度的增加而增大,然后用最小二乘法拟合了二者的对应关系。由横梁的损伤程度可确定横梁初始疲劳裂纹尺寸,进而可由Paris公式预测振动筛横梁的疲劳裂纹扩展剩余寿命。应变模态变化率作为损伤诊断指标具有敏感、可靠的优点,可以较好地确定横梁损伤位置和损伤程度。对振动筛横梁的裂纹扩展剩余寿命的预测,可为横梁的预报维修提供参考,以保证振动筛的安全可靠运行。
[Abstract]:Based on the modal theory, the displacement and strain modal analysis of the vibrating screen beam is carried out. The results show that the relative deviation of the same modal frequency before and after the damage of the cross beam is small, and there is no obvious change of the displacement modal mode. However, the peak value of the strain mode appears after the beam is damaged. According to this, the strain mode change rate is constructed as a diagnostic index of beam damage. The analysis results show that the strain mode change rate increases with the increase of beam damage degree, and the corresponding relationship between them is fitted by the least square method. The initial fatigue crack size of the cross beam can be determined by the damage degree of the beam, and the residual fatigue crack propagation life of the vibrating screen cross beam can be predicted by the Paris formula. As a damage diagnosis index, the strain mode change rate has the advantages of sensitivity and reliability, and can be used to determine the damage location and damage degree of the beam. The prediction of the residual life of crack growth of the vibrating screen beam can provide reference for the prediction and maintenance of the cross beam, so as to ensure the safe and reliable operation of the vibrating screen.
【作者单位】： 青岛科技大学机电工程学院;
【基金】：国家自然科学基金(51074094) 山东省自然科学基金(ZR2015EM035)资助项目
【分类号】：TD452
，
本文编号：2457343
[Abstract]:Based on the modal theory, the displacement and strain modal analysis of the vibrating screen beam is carried out. The results show that the relative deviation of the same modal frequency before and after the damage of the cross beam is small, and there is no obvious change of the displacement modal mode. However, the peak value of the strain mode appears after the beam is damaged. According to this, the strain mode change rate is constructed as a diagnostic index of beam damage. The analysis results show that the strain mode change rate increases with the increase of beam damage degree, and the corresponding relationship between them is fitted by the least square method. The initial fatigue crack size of the cross beam can be determined by the damage degree of the beam, and the residual fatigue crack propagation life of the vibrating screen cross beam can be predicted by the Paris formula. As a damage diagnosis index, the strain mode change rate has the advantages of sensitivity and reliability, and can be used to determine the damage location and damage degree of the beam. The prediction of the residual life of crack growth of the vibrating screen beam can provide reference for the prediction and maintenance of the cross beam, so as to ensure the safe and reliable operation of the vibrating screen.
【作者单位】： 青岛科技大学机电工程学院;
【基金】：国家自然科学基金(51074094) 山东省自然科学基金(ZR2015EM035)资助项目
【分类号】：TD452
，
本文编号：2457343
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