Research On The Structural Reliability Of Equipments In The Non-Gaussian Vibration Environment

During the transportation of various kinds of equipments, the vibration is generatedby random road excitation, which may cause the structural fatigue failure and thus havesome effects on the performance index of equipments. In the engineering research,thetransport vibration of various kinds of equipments used to be simply approximated tothe random vibration with Gaussian distribution. However, a lot of vibration caused bypoor road conditions often can not be simply approximated to Gaussian distribution, butshowing a significant non-Gaussian distribution characteristics. Compared with thetraditional Gaussian random vibration, the non-Gaussian random vibration has a verydifferent amplitude distribution and some different characteristics .Thus it would have aunnegligible impact on the structural reliability of equipments. Based on the modernanalysis theory of random vibration fatigue and the non-Gaussian random vibrationsimulation method as well as taking the finite element analysis and vibration testing asthe means, this paper focuses the theme on " the structural reliability of equipments inthe non-Gaussian vibration environment " to do some research from the followingaspects:(1)This paper has done some research on the fatigue life analysis method under thenon-Gaussian random loading, which is also achieved in the engineering. After makinga systematic analysis of the existing time-domain and frequency-domain analysismethods of fatigue life, the paper has proposed a new non-Gaussian random vibrationfatigue analysis method that is based on Monte-Carlo simulation. The paper also hasused this method to make a secondary development of the finite element simulationsoftware MSC. To be more specific, the PCL language is used to design the non-Gaussian vibration fatigue simulation module to make the finite element simulationsoftware have a new function of analyzing the non-Gaussian vibration fatigue life(2) The paper has created a systematic non-Gaussian random vibration numericalsimulation method which also has been applied in engineering. After analyzing the IFFT transformation-based Gaussian random loading simulation method and the secondphase modulation-based super-Gaussian random loading simulation method, a new sub-Gaussian random loading numerical simulation method by adjusting the amplitudedistribution and replacing the phase is proposed. This method uses the mutualdecoupling principle of frequency domain parameters (power spectral density) and theamplitude domain parameters (kurtosis, skewness) and has been applied to thedevelopment of a new non- Gaussian vibration controller.(3) Two means of simulation and experimental research have been used to revealthe impact of the structural fatigue damage caused by non-Gaussian characteristics. Thetypical structural component has been selected to do the fatigue life simulation analysis respectively under the Gaussian, super-Gaussian and sub-Gaussian random loadings,based on the developed simulation module for non-Gaussian vibration fatigue analysis.After that, the simulation results were tested using the developed non-Gaussian vibrationcontroller. With all above work, the impact of the structural fatigue damage made bynon-Gaussian characteristics were achieved.In summary, this paper takes the non-Gaussian loading fatigue analysis methodand the non-Gaussian loading numerical simulation method as the main content, on thebackground of road transportation tests of equipments. On the base, the paper revealsthe impact of the structural fatigue damage caused by non-Gaussian characteristicsthrough the means of simulation and experiment which could provide guidance to theaccurate and scientific implementation of indoor vehicle road simulation tests.