Statisticalanalysis Of Vibration Transmission Characteristics Considering Parameter Uncertainty

This paper focuses on the dynamic system of the plate-shell structure considering the parameter uncertainty,and conducts in-depth research on the statistical analysis of vibration transmission characteristics.The main work is as follows:Due to the randomness of the structural parameters of the parameter uncertainty system,the randomness of the vibration transmission characteristics is the main factor affecting the vibration transmission path.In this paper,we use stochastic finite element method,based on Nataf numerical transformation theory,using Cholesky decomposition and Gauss-Hermite numerical integration method to convert non-Gauss stochastic processes to Gauss stochastic processes,and use stochastic finite element matrix to represent discrete stochastic process features.Then,discrete random process features are represented by a stochastic finite element matrix.The establishment of the transfer function is a key part of the analysis method of vibration transmission with parametric uncertainties.The vibration transfer function of the system is studied in depth and a vibration transfer analysis method considering the parameter uncertainty is proposed.The parameter uncertainty is realized.Statistical analysis of vibration transmission characteristics of structures.In this paper,the Fourier-Hermite polynomial expansion and the Gauss-Hermite numerical integration method are studied in depth.The vibration transfer function of the plate-shell structure with uncertain parameters is established,and the origin transmission and cross-point transmission characteristics of the excitation point are estimated,combined with finite element software analysis.And numerical software analysis,compared with Monte Carlo simulation results,obtained comparative analysis of vibration transfer analysis.Based on this,this paper combines the Fourier-Hermite polynomial expansion and modal superposition principle,proposes a dynamic polynomial chaotic(PC)expansion method,and performs statistical energy analysis on the dynamic system of plate and shell structure.The analysis results show that statistical analysis of random system vibration transmission on narrow-band spectrum and wide-spectrum spectrum is in good agreement with Monte Carlo simulation results;the phenomenon of amplitude fluctuation of narrow-band spectral dynamic flexibility caused by random fluctuation of resonance frequency will be due to broadband The energy is superimposed and weakened,which makes the proposed PC method the latter analysis result more effective than the former analysis result.The PDFs given by the PC expansion method based on random dynamic compliance all have a shape bias,which manifests itself as the relative error of statistical analysis of vibration transfer.In the low-middle-frequency vibrationtransfer analysis,it is recommended that the proposed PC method be used to analyze the vibration transmission of the narrowband spectrum and the broadband spectrum at the same time.