The frequency domain estimate of fatigue damage of combined load effects based on the rain-flow counting

2017 ◽  
Vol 52 ◽  
pp. 34-49 ◽  
Author(s):  
Wenbo Huang
Keyword(s):  
Frequency Domain ◽  
Fatigue Damage ◽  
Combined Load ◽  
Load Effects

Critical Evaluation of Frequency-Domain Approach for Fatigue Damage Estimation

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Gašper Vidic ◽  
Marko Nagode
Keyword(s):  
Frequency Domain ◽  
Fatigue Damage ◽  
Input Data ◽  
Critical Evaluation ◽  
High Amplitude ◽  
Damage Estimation ◽  
Accumulated Damage ◽  
Power Spectral ◽  
History Of ◽  
Frequency Domain Approach

Frequency-domain approach for fatigue damage estimation and lifetime prediction of mechanical components is often used for its computational efficiency and the capability to give a synthetic representation of a random process. The problem with the approach is that the input data, the stress power spectral density (PSD), may not include the information about potential small amount of high amplitude cycles which can substantially increase the accumulated fatigue damage. The paper investigates the scatter of the accumulated damage in generated random stress histories and compares them to the results obtained by a frequency-domain approach—the Dirlik method. The results show a possibility of a severe underestimation of accumulated damage when using frequency-domain approach. In case a typical stress, history of a certain mechanical component includes sporadic high amplitude cycles their effect shoud be taken into consideration when using frequency-domain approach.

Research and analysis of the wheeled vehicle load spectrum editing method based on short-time Fourier transform

2019 ◽  
Vol 233 (14) ◽  
pp. 3671-3683
Author(s):  
Zongkai Liu ◽  
Chuan Peng ◽  
Xiaoqiang Yang
Keyword(s):  
Fourier Transform ◽  
Frequency Domain ◽  
Fatigue Damage ◽  
Time Domain ◽  
Short Time Fourier Transform ◽  
Load Spectrum ◽  
Statistical Parameters ◽  
Original Spectrum ◽  
The Time Domain ◽  
Short Time

The measured uniaxial-head load spectrum in the road simulation test has a large number of useless small loads. When applying the measured load spectrum directly, it will take a lot of time. This paper designs a comprehensive road spectrum measurement system to collect data and proposes a method for editing the uniaxial-head acceleration load spectrum using short-time Fourier transform to speed up the reliability test process and reduce time costs. In this method, the time domain and frequency domain information of the signal is obtained by short-time Fourier transform. The concept of accumulated power spectral density is proposed to identify the reduced load data, and the relative fatigue damage is used as the pass criterion. The length of the edited spectrum is only 66% of the original spectrum through the above-mentioned editing method and retains the relative damage amount of 91%. Finally, through the analysis of time domain, frequency domain, and fatigue statistical parameters, it demonstrates that the short-time Fourier transform–based acceleration load spectrum edition method could achieve a similar fatigue damage to the original spectrum in a shorter time.

scholarly journals Fatigue analysis of a bridge deck using the peaks-over-threshold approach with application to the Millau viaduct

2020 ◽  
Vol 2 (8) ◽  
Author(s):  
Mariia Nesterova ◽  
Franziska Schmidt ◽  
Christian Soize
Keyword(s):  
Fatigue Damage ◽  
Extreme Values ◽  
Initial Distribution ◽  
Linear Extrapolation ◽  
Peaks Over Threshold ◽  
Innovative Method ◽  
Structural Details ◽  
Load Effects ◽  
Existing Bridges ◽  
Threshold Approach

AbstractUsually, to estimate the fatigue life of structural details in existing bridges, fatigue damage assessed with monitoring data is extrapolated linearly in time. In this study, a methodology is proposed for predicting the numbers of fatigue cycles with the peaks-over-threshold approach. On the other side, this POT approach, which is based on extreme values, is, as usually, also used to predict the load effects of extreme amplitude. This provides an innovative method to predict fatigue damage, which considers the initial distribution of numbers of cycles over time. It may account for traffic growth in volume and mass. This paper shows the comparison between reliability indexes assessed with the proposed method and the linear extrapolation.

scholarly journals DEVELOPMENT OF A NEW FATIGUE DAMAGE MODEL FOR QUARTER-MODAL SPECTRA IN FREQUENCY DOMAIN

Brodogradnja ◽  
2020 ◽  
Vol 71 (1) ◽  
pp. 39-57
Author(s):  
Sang Woo Kim ◽  
◽  
Seung Jae Lee
Keyword(s):  
Frequency Domain ◽  
Fatigue Damage ◽  
Damage Model

scholarly journals A Study on Frequency Domain Fatigue Damage Prediction Models for Wide-Banded Bimodal Stress Range Spectra

2011 ◽  
Vol 48 (4) ◽  
pp. 299-307 ◽  
Author(s):  
Jun-Bum Park ◽  
Chan-Hoe Kang ◽  
Kyung-Su Kim ◽  
Joon-Mo Choung ◽  
Chang-Hyuk Yoo
Keyword(s):  
Frequency Domain ◽  
Fatigue Damage ◽  
Prediction Models ◽  
Stress Range ◽  
Damage Prediction

Monte Carlo Prediction of the Extreme Values of the Combined Load Effect and Semi-Probabilistic Design of Ocean-Going Ships

2013 ◽  
Author(s):  
Wenbo Huang ◽  
Ying Xiao
Keyword(s):  
Monte Carlo ◽  
Extreme Values ◽  
Empirical Distribution ◽  
Extreme Value Distribution ◽  
Distribution Model ◽  
Wave Load ◽  
Load Effect ◽  
Combined Load ◽  
Load Combination ◽  
Load Effects

Based on Poisson models, the Monte Carlo simulation of the combined still-water and wave load effects is carried out to estimate extreme values of the combined load effects of oceangoing ships. The extreme values predicted are compared with those based on the theoretical methods. The numerical analyses show that the results based on the two methods agree with very well. Moreover, the empirical distribution of the combine extreme values simulated and numerical theoretical distribution based on a load combination analysis can both be well fitted to an analytical extreme value distribution model of Type II. Besides, a strength model of a ship hull beam is developed based on the fatigue analyses. Finally, with the models developed for load effect and strength, the simplified reliability analyses are carried out for an ocean going ship.

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