Reliability Analysis And Optimization Design Of Mistuning Blisk Vibration

Blisk is an important part of aero engine,ideally,it is designed to be symmetrical,Mistuning is an inevitably factor of the blisk because of the factor of material dispersibility,manufacturing error,wear and tear.At present,the mainly analysis of mistuning blisk is mistuning identification and localization,the reliability analysis of mistuning blisk is rarely studied,and the current reliability analysis method cannot satisfy the requirements of reliability analysis for strong non-linear structure.so it is very urgent to develop new reliability analysis method.The purpose of studying the effect of mistuning on blisk vibration and its reliability analysis is to provide guidance for blisk design.The ultimate goal is to improve the reliability of blisk,so it is necessary to optimize the design of blisk.The main contents of this paper are as follows:(1)Study on mistuning blisk vibration statistic analysis based on extreme response method.In order to explore the effect of mistuning on the mode and vibration response of blisk,the finite element method is used to solving the mode and vibration response to comparing the effect of different mistuning degree on mode and vibration response of blisk,and proposes the mode localization factor and the vibration factor to quantify the localization degree of mistuning blisk.The extreme response surface is used to explore the mode and vibration response probability characteristics of mistuning blisk.Statistical analysis of the sampling results to explore the probabilistic characteristics of blisk modal and vibration response under the influence of uncertain factors.(2)Study on mistuning blisk vibration reliability analysis based on radial basis function extreme response method.For the above problem,Extreme response surface method(RBFERSM)is proposed by combining the radial basis function artificial neural nets(RBFANN)with extreme response surface method(ERSM).The results show that vibration reliability of the blisk is reduced and the vibration failure is more likely to occur.By comparing with MCM and ERSM,it concluded that RBFERSM can improve the calculation efficiency on the premise of ensuring the accuracy of calculation.The reliability is obtained.(3)Optimization on mistuning blisk vibration reliability design based on genetic algorithm-extreme response method.In this paper,initiative mistuning is introduced into the blisk design,harmonic mistuning is adopted as the initiative mistuning form.The finite element method is used to analyzed the initiative blisk vibration.The result show that initiative mistuing reduces the localization of blisk by 23%.The appropriate variables are selected,the RBFERSM is constructed with the sample points,which are sampled by Latin hypercube sampling method.The sensitivity analysis of the initiative blisk is carry out,and the input variable with large influence probability on blisk is selected as the optimistic factor,and the optimistic design model of initiative blisk reliability is established.The genetic algorithm and the RBFERSM are combined as optimistic method.The optimistic result show that the standard deviation of blisk vibration deformation is reduced by 29.15%,and the reliability is increased to 99.73%.