Probabilistic Model for Remaining Fatigue Life Estimation of Bridge Components

2021 ◽  
Vol 147 (10) ◽  
pp. 04021147
Author(s):  
Guru Prakash
2021 ◽  
Vol 231 ◽  
pp. 111760
Author(s):  
Emad Norouzzadeh Tochaei ◽  
Zheng Fang ◽  
Todd Taylor ◽  
Saeed Babanajad ◽  
Farhad Ansari

2019 ◽  
Vol 18 (5-6) ◽  
pp. 1889-1902 ◽  
Author(s):  
Hyung Jin Lim ◽  
Hoon Sohn

This article presents an online remaining fatigue life estimation (prognosis) technique using nonlinear ultrasonic modulation. When two ultrasonic inputs at two distinct frequencies are introduced to a structure with a fatigue crack, modulation components at the sum and difference of input frequencies are generated owing to crack opening and closing. First, a fatigue index is defined for prognosis and extracted from nonlinear ultrasonic modulation measurement. Subsequently, it is shown that the fatigue index is expressed as a simple power function of loading cycles applied to a target structure based on the Nazarov–Sutin and Paris–Erdogan theories. Then, the real-time remaining fatigue life estimation method is proposed by fitting the power function to online data obtained from the target structure. The performance of the proposed prognosis technique is evaluated using either notched or welded aluminum (6061-T6) plate specimens.


Author(s):  
Xintian Liu ◽  
Yang Qu ◽  
Xiaobing Yang ◽  
Yongfeng Shen

Background:: In the process of high-speed driving, the wheel hub is constantly subjected to the impact load from the ground. Therefore, it is important to estimate the fatigue life of the hub in the design and production process. Objective:: This paper introduces a method to study the fatigue life of car hub based on the road load collected from test site. Methods:: Based on interval analysis, the distribution characteristics of load spectrum are analyzed. The fatigue life estimation of one - dimensional and two - dimensional load spectra is compared by compiling load spectra. Results:: According to the S-N curve cluster and the one-dimensional program load spectrum, the estimated range fatigue life of the hub is 397,100 km to 529,700 km. For unsymmetrical cyclic loading, each level means and amplitude of load were obtained through the Goodman fatigue empirical formula, and then according to S-N curve clusters in the upper and lower curves and two-dimensional program load spectrum, estimates the fatigue life of wheel hub of the interval is 329900 km to 435200 km, than one-dimensional load spectrum fatigue life was reduced by 16.9% - 17.8%. Conclusion:: This paper lays a foundation for the prediction of fatigue life and the bench test of fatigue durability of auto parts subjected to complex and variable random loads. At the same time, the research method can also be used to estimate the fatigue life of other bearing parts or high-speed moving parts and assemblies.


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