Prediction of Minimum Life Point of Resonance Fatigue and Experimental Verification of the Centrifugal Impeller
Higher-order modes have a great influence on high-period fatigue failure,but there are few previous studies on the vibration characteristics of centrifugal impellers in higher-order modes.In this study,a finite element model of the centrifugal impeller is established,and the accuracy of the model is verified by frequency measurement test.Then the centrifugal impeller high-order vibration characterization is carried out to obtain the location of the minimum life point.Finally,the trial test is carried out to analyze the characteristics of the impeller crack and verify the reasonableness of the method for determining the location of the danger point.The results show that the error between the simulated and tested results of the main 1st order intrinsic frequency of the centrifugal impeller is only 1.2％.The maximum relative stress of the impeller is located at the root of the main blade on the exhaust side,where is the danger point of resonance fatigue.The nature of the impeller crack is high-frequency fatigue crack,and the crack originates at the root of the exhaust side leaf,which is consistent with the finite element analysis results.The test results justify the use of vibration stress at resonance frequency to predict its resonance fatigue minimum life point.The conclusions of this study can provide theoretical basis and technical support for the design and improvement of centrifugal impeller.
centrifugal impellerhigher order modesfatigue crackingresonanceprediction of minimum life point
万方数据
维普
