Experimental Modal Analysis On S31 Roots Blower Casing

Roots blower is widely used in various industry departments because of its simple structure and stable operation.But vibration and noise problems of Roots blower are very obvious.In order to optimize the dynamic performance of blower structure and achieve the goal of vibration noise reduction,the modal test is carried out with casing of S31 Roots blower according to the experimental modal analysis theory.Combined with finite element analysis for comparative study,the effectiveness of experimental methods and accuracy of results is verified.Modal analysis method provide the basis for evaluating the dynamic performance of blower casing.The main contents is as follows:1)The experimental modal theory and testing technology of the Boots blower casing are analyzed,including the vibration measurement and signal processing methods.2)Study on method of hammer experiment and do some comparative analysis with different hammer materials,then choose the percussion material for experiments of this paper.The influence of different incentive methods to structure modal experimental is analyzed through experimental instances.Finally choose the optimal incentive way.3)Do research on the principle of different parameter identification methods.And summarizes the key points of choosing identification methods by different test applications.4)Study on the effects of window functions for experiment results with window theory and analyze some experimental instances with different window functions.The principles of choosing window is summarized and a applicable window function is selected for experiments of this paper.5)Roots blower casing modal is established by the modal experiment software.Then achieving the modal frequency,modal damping and modal vibration mode with modal analysis.6)Modal parameters and vibration mode of experiments were compared with the results of the finite element analysis.To verify the correctness of experiment methods and the effectiveness of the experimental results.This paper will provide essential parameters and basis for optimization of the Roots blower casing.And it has great reference value for future experimental modal analysis of complex shell structures.