Vibration response prediction of coated blisks under multi-point non-contact excitations using mistuning identification data

The mistuning and excitations of the real engineering coated blisk are very complex and it is difficult to predict the vibration response. In this study, a numerical method of response prediction for coated blisks under multi-point non-contact excitations is proposed. The purpose of applying multi-point non-contact excitations to the blades is to get closer to the actual excitations condition of coated blisks. A non-rotating coated academic blisk is used as the research object, the component mode mistuning (CMM) reduced-order technique focusing on blade mistuning is improved to establish the response prediction model of the coated blisk, which includes quantized parameters of the blade substrate mistuning and the mistuning caused by coating. Meanwhile, the effects of the mass, stiffness and damping mistuning of the blisk substrate and the coating on the response are comprehensively considered in the model. In order to preserve the simulation accuracy of the response prediction model, the blade substrate mistuning and the mistuning caused by coating are identified, and the reduced-order model (ROM) is updated by the identification results of mass and stiffness mistuning. The response predictions of the numerical case and actual case of the non-rotating simplified coated academic blisk are carried out respectively. For the numerical case, the results of response prediction are in good agreement with the response calculation results of the high fidelity finite element model (FEM). Compared with the numerical case, the error between the predicted response and the tested response is larger, but this error level is sufficient to meet the requirements of engineering applications. All the results show that the proposed method is effective for predicting the response of the non-rotating coated academic blisks under multi-point excitations.