【摘要】：基于模態(tài)理論對(duì)振動(dòng)篩橫梁進(jìn)行了位移和應(yīng)變模態(tài)分析,結(jié)果表明橫梁損傷前、后同階模態(tài)頻率的相對(duì)偏差較小,位移模態(tài)振型亦無明顯突變,而應(yīng)變模態(tài)振型在橫梁損傷后產(chǎn)生了突變峰值。據(jù)此構(gòu)建了應(yīng)變模態(tài)變化率作為橫梁損傷診斷指標(biāo),分析結(jié)果表明應(yīng)變模態(tài)變化率隨橫梁損傷程度的增加而增大,然后用最小二乘法擬合了二者的對(duì)應(yīng)關(guān)系。由橫梁的損傷程度可確定橫梁初始疲勞裂紋尺寸,進(jìn)而可由Paris公式預(yù)測振動(dòng)篩橫梁的疲勞裂紋擴(kuò)展剩余壽命。應(yīng)變模態(tài)變化率作為損傷診斷指標(biāo)具有敏感、可靠的優(yōu)點(diǎn),可以較好地確定橫梁損傷位置和損傷程度。對(duì)振動(dòng)篩橫梁的裂紋擴(kuò)展剩余壽命的預(yù)測,可為橫梁的預(yù)報(bào)維修提供參考,以保證振動(dòng)篩的安全可靠運(yùn)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.
【作者單位】： 青島科技大學(xué)機(jī)電工程學(xué)院;
【基金】：國家自然科學(xué)基金(51074094) 山東省自然科學(xué)基金(ZR2015EM035)資助項(xiàng)目
【分類號(hào)】：TD452
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本文編號(hào)：2457343