Fatigue Life Analysis Under Non-Gaussian Random Vibration Excitation

2021 ◽  
pp. 81-122
Author(s):  
Yu Jiang ◽  
Junyong Tao ◽  
Xun Chen
Keyword(s):  
Fatigue Life ◽  
Random Vibration ◽  
Vibration Excitation ◽  
Life Analysis ◽  
Fatigue Life Analysis ◽  
Non Gaussian

Fatigue Life Analysis of Vehicle Systems under Non-Gaussian Excitation

2020 ◽  
Vol 17 (2) ◽  
pp. 7956-7966
Author(s):  
Z. Yang ◽  
D. Zhu ◽  
Q. Gao ◽  
L. Gong ◽  
D. Xu
Keyword(s):  
Monte Carlo ◽  
Fatigue Life ◽  
Equations Of Motion ◽  
Principal Component ◽  
Correlation Structure ◽  
Vehicle Systems ◽  
Life Analysis ◽  
Fatigue Life Analysis ◽  
Non Gaussian ◽  
First Four Moments

Fatigue life analysis is an important work in manufacturing of vehicle systems. The traditional method is to assume that stochastic loads are Gaussian type, then fatigue life is calculated by rain-flow counting, S-N curve and Miner linear damage rule. However, it is difficult to acquire accurate results by this means. In this paper, a numerical methodology is used to simulate non-Gaussian loads considering effects of skewness and kurtosis, as well as to estimate fatigue life under non-Gaussian stresses. Firstly, non-Gaussian inputs are represented by polynomial chaos expansion (PCE) and Karhunen-Loeve (KL) expansion when they are characterised using first four moments, i.e. mean, variance, skewness, kurtosis and a given correlation structure. During this process, we propose spectral decomposition to eliminate the influence of potential imaginary numbers, principal component analysis is also proposed to simplify calculating procedure in KL. Besides, original Monte Carlo sampling is replaced by quasi Monte-Carlo (QMC), which could greatly reduce the workload of numerical simulations. In order to get first four moments and correlation structure of outputs, differential equations of motion are numerically integrated by Runge-Kutta method. Meanwhile, response trajectories are represented based on PCE-KL-QMC approach. Eventually, the rain-flow counting is applied into these trajectories to obtain fatigue life variables, and a convenient formula about the saddlepoint approximations (SPA) represented by first four moments is proposed to provide fatigue life PDF. According to the above way, accurate and effective fatigue life estimation results can be presented

scholarly journals Experimental Design and Validation of an Accelerated Random Vibration Fatigue Testing Methodology

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yu Jiang ◽  
Gun Jin Yun ◽  
Li Zhao ◽  
Junyong Tao
Keyword(s):  
Fatigue Life ◽  
Stress Responses ◽  
Life Prediction ◽  
Random Vibration ◽  
Fatigue Testing ◽  
Fatigue Tests ◽  
Fatigue Life Prediction ◽  
Power Spectral ◽  
Vibration Fatigue ◽  
Non Gaussian

Novel accelerated random vibration fatigue test methodology and strategy are proposed, which can generate a design of the experimental test plan significantly reducing the test time and the sample size. Based on theoretical analysis and fatigue damage model, several groups of random vibration fatigue tests were designed and conducted with the aim of investigating effects of both Gaussian and non-Gaussian random excitation on the vibration fatigue. First, stress responses at a weak point of a notched specimen structure were measured under different base random excitations. According to the measured stress responses, the structural fatigue lives corresponding to the different vibrational excitations were predicted by using the WAFO simulation technique. Second, a couple of destructive vibration fatigue tests were carried out to validate the accuracy of the WAFO fatigue life prediction method. After applying the proposed experimental and numerical simulation methods, various factors that affect the vibration fatigue life of structures were systematically studied, including root mean squares of acceleration, power spectral density, power spectral bandwidth, and kurtosis. The feasibility of WAFO for non-Gaussian vibration fatigue life prediction and the use of non-Gaussian vibration excitation for accelerated fatigue testing were experimentally verified.

Fatigue life analysis of shot-peened bearing steel

2012 ◽  
Vol 26 (6) ◽  
pp. 1747-1752 ◽  
Author(s):  
Sang-Jae Yoon ◽  
Jung-Hoon Park ◽  
Nak-Sam Choi
Keyword(s):  
Fatigue Life ◽  
Bearing Steel ◽  
Life Analysis ◽  
Fatigue Life Analysis
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