An Approach Based on Frequency Domain for Random Vibration Fatigue Life Estimation

2014 ◽  
pp. 1425-1435
Author(s):  
Jing Hailong ◽  
Chen Yunxia ◽  
Kang Rui
Keyword(s):  
Fatigue Life ◽  
Frequency Domain ◽  
Random Vibration ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
Vibration Fatigue

Fatigue Life Estimation Using Frequency Domain Technique and Probabilistic Linear Cumulative Damage Model

2020 ◽  
Author(s):  
Vagner Pascualinotto Junior ◽  
Diego Felipe Sarzosa Burgos
Keyword(s):  
Fatigue Life ◽  
Frequency Domain ◽  
Structural Component ◽  
Random Vibration ◽  
Fatigue Behavior ◽  
Pressure Vessels ◽  
Nuclear Industry ◽  
Material Behavior ◽  
Life Estimation ◽  
Fatigue Life Estimation

Abstract Engineering critical structures, such as pressure vessels and pipelines, are designed to withstand a variety of in-service loading specific to their intended application. Random vibration excitation is observed in most of the structural component applications in the offshore, aerospace, and nuclear industry. Likewise, fatigue life estimation for such components is fundamental to verify the design robustness assuring structural integrity throughout service. The linear damage accumulation model (Palmgren-Miner rule) is still largely used for damage assessment on fatigue estimations, even though, its limitations are well-known. The fact that fatigue behavior of materials exposed to cyclic loading is a random phenomenon at any scale of description, at a specimen scale, for example, fatigue initiation sites, inclusions, defects, and trans-granular crack propagation are hardly predicted, indicates that a probabilistic characterization of the material behavior is needed. In this work, the methodology was applied to a Titanium alloy structural component. Low alloyed titanium alloys have no tendency to corrosion cracking in high-temperature high-pressure water containing impurities of chloride and oxygen found in a steam generator of nuclear power plants. The inherent uncertainties of the fatigue life and fatigue strength of the material are characterized using the random fatigue limit (RFL) statistic method. Furthermore, a frequency domain technique is used to determine the response power spectrum density (PSD) function of a structural component subjected to a random vibration profile excitation. The fatigue life of the component is then estimated through a probabilistic linear damage cumulative model.

scholarly journals Time and frequency domain models for multiaxial fatigue life estimation under random loading

2015 ◽  
Vol 9 (33) ◽  
pp. 376-381 ◽  
Author(s):  
Andrea Carpinteri ◽  
Andrea Spagnoli ◽  
Camilla Ronchei ◽  
Sabrina Vantadori
Keyword(s):  
Fatigue Life ◽  
Frequency Domain ◽  
Multiaxial Fatigue ◽  
Random Loading ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
Domain Models

scholarly journals Application of Spectral Method for Vibration-Induced High-Cycle Fatigue Evaluation of an HP Turbine Blade

2020 ◽  
Author(s):  
Iroizan Ubulom
Keyword(s):  
Fatigue Life ◽  
Frequency Domain ◽  
Turbine Blade ◽  
Euler Angle ◽  
Mean Stress ◽  
Critical Plane ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
The Mean ◽  
Fully Coupled

Abstract A method of fluid-structure interaction coupling is implemented for a forced-response, vibration-induced fatigue life estimation of a high-pressure turbine blade. Two simulations approaches; a two-way (fully-coupled) and one-way (uncoupled) methods are implemented to investigate the influence of fluidsolid coupling on a turbine blade structural response. The fatigue analysis is performed using the frequency domain spectral moments estimated from the response power spectral density of the two simulation cases. The method is demonstrated in light of the time-domain method of the rainflow cycle counting method with mean stress correction. Correspondingly, the mean stress and multiaxiality effects are also accounted for in the frequency domain spectral approach. In the mean stress case, a multiplication coefficient is derived based on the Morrow equation, while the case of multiaxiality is based on a criterion which reduces the triaxial stress state to an equivalent uniaxial stress using the critical plane assumption. The analyses show that while the vibration-induced stress histories of both simulation approaches are stationary, they violate the assumption of normality of the frequency domain approaches. The stress history profile of both processes can be described as platykurtic with the distributions having less mass near its mean and in the tail region, as compared to a Gaussian distribution with an equal standard deviation. The fully-coupled method is right leaning with positive skewness while the uncoupled approach is left leaning with negative skewness. The directional orientation of the principal axes was also analyzed based on the Euler angle estimation. Although noticeable differences were found in the peak distribution of the normal stresses for both methods, the predicted Euler angle orientations were consistent in both cases, depicting a similar orientation of the critical plane during a crack initiation process. It is shown that the fatigue life estimation was conservative in the fully-coupled solution approach.

scholarly journals Efficient frequency-domain based fatigue life estimation of spot welds in vehicle components

2019 ◽  
Vol 83 (4) ◽  
pp. 921-931
Author(s):  
Milan Zigo ◽  
Eray Arslan ◽  
Werner Mack ◽  
Gerhard Kepplinger
Keyword(s):  
Fatigue Life ◽  
Frequency Domain ◽  
Spot Welds ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
Vehicle Components
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