scholarly journals Bayesian Fatigue Life Prediction of Corroded Steel Reinforcing Bars

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Wei Wang ◽  
Jie Chen ◽  
Bo Diao ◽  
Xuefei Guan ◽  
Jingjing He ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Fatigue Testing ◽  
Fatigue Life Prediction ◽  
Model Parameters ◽  
Reinforcing Bars ◽  
Baseline Model ◽  
Standard Specimens ◽  
Life Model ◽  
Log Linear

This paper presents a general method for fatigue life prediction of corroded steel reinforcing bars. A fatigue testing on standard specimens with pitting corrosion is carried out to obtain corrosion fatigue data. The maximum corrosion degree (MCD), characterizing the most severe site of the corrosion pit, is identified to have a log-linear relationship with the fatigue life. A fatigue life model incorporating the MCD and the stress range for corroded steel reinforcing bars is proposed. The model parameters are identified using the testing data, and the model is considered as the baseline model. To utilize the proposed model for life prediction of corroded steel reinforcing bars with different geometries and working conditions, the Bayesian method is employed to update the baseline model. The effectiveness of the overall method is demonstrated using independent datasets of realistic steel reinforcing bars.

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.

scholarly journals Recent Developments on the Unified Fatigue Life Prediction Method Based on Fracture Mechanics and its Applications

2020 ◽  
Vol 8 (6) ◽  
pp. 427 ◽  
Author(s):  
Fang Wang ◽  
Weicheng Cui
Keyword(s):  
Fatigue Life ◽  
Fracture Mechanics ◽  
Crack Growth ◽  
Life Prediction ◽  
Structural Reliability ◽  
Influential Factors ◽  
Fatigue Life Prediction ◽  
Model Parameters ◽  
Sensitivity Index ◽  
Marine Structure

Safety analysis and prediction of a marine structure is of great concern by many stakeholders and the general public. In order to accurately predict the structural reliability of an in-use marine structure, one needs to calculate accurately the fatigue crack growth at any service time. This can only be possible by using fracture mechanics approach and the core of fracture-mechanics-based method is to establish an accurate crack growth rate model which must include all the influential factors of the same order of sensitivity index. In 2011, based on the analysis of various influencing factors, the authors put forward a unified fatigue life prediction (UFLP) method for marine structures. In the following ten years of research, some further improvements of this method have been made and the applications of this UFLP are carried out. In this paper, these progresses are reported and its underlying principles are further elaborated. Some basic test data used to determine model parameters are also provided.

Fatigue life prediction for automobile stabilizer bar

2019 ◽  
Vol 11 (2) ◽  
pp. 303-323
Author(s):  
Shuangshuang Li ◽  
Xintian Liu ◽  
Xiaolan Wang ◽  
Yansong Wang
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Test Sample ◽  
Fatigue Life Prediction ◽  
Bench Test ◽  
Load Spectrum ◽  
Content Type ◽  
Life Model ◽  
On The Road ◽  
The Impact

Purpose During the running of automobile, the stabilizer bar is frequently subjected to the impact of complex random loads, which is prone to fatigue failure and accident. In regard to this, the purpose of this paper is to study and discuss fatigue life of automobile stabilizer bar. Design/methodology/approach Durability bench test shows that failure is located at the joint of sleeve and stabilizer bar body. Based on the collection and compilation of micro-strain load spectrum of the stabilizer bar, the strain-life model is studied considering the influence of average stress and maximum stress at failure area. Seven-grade strain-life curves of the stabilizer bar are established. According to the principle of linear damage accumulation, the relationship between fatigue life and damage is discussed, then the fatigue life of stabilizer bar is predicted. Fatigue life evaluation is carried out from three aspects: reliability analysis, static analysis and fatigue life simulation. Findings The results show that the reliability of the test sample is 99.9 percent when the confidence is 90 percent and the durability is 1,073 load spectrum cycles; the ratios of predicted and simulated life to design life are 2.77 and 2.30, respectively. Originality/value Based on the road load characteristics of automobile stabilizer bar, the method of fatigue life prediction and evaluation is discussed, which provides a basis for the design and development of automobile chassis components.

A nonlinear constant life model for the fatigue life prediction of composite structures

2014 ◽  
Vol 23 (4) ◽  
pp. 337-350 ◽  
Author(s):  
T. Park ◽  
M. Kim ◽  
B. Jang ◽  
J. Lee ◽  
J. Park
Keyword(s):  
Fatigue Life ◽  
Composite Structures ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Life Model

scholarly journals An Energy-Based Experimental-Analytical Torsional Fatigue Life-Prediction Method

2010 ◽  
Author(s):  
John N. Wertz ◽  
M.-H. Herman Shen ◽  
Tommy George ◽  
Charles Cross ◽  
Onome Scott-Emuakpor
Keyword(s):  
Fatigue Life ◽  
Strain Energy ◽  
Life Prediction ◽  
Fatigue Testing ◽  
Pure Shear ◽  
Prediction Method ◽  
Strain Curve ◽  
Fatigue Life Prediction ◽  
Torsional Fatigue ◽  
Shear Fatigue

An energy-based fatigue life prediction framework for calculation of torsional fatigue life and remaining life has been developed. The framework for this fatigue prediction method is developed in accordance with our previously developed energy-based axial and bending fatigue life prediction approaches, which state: the total strain energy dissipated during a monotonic fracture and cyclic processes is the same material property, where each can be determined by measuring the area underneath the monotonic true stress-strain curve and the area within a hysteresis loop, respectively. The energy-based fatigue life prediction framework is composed of the following entities: (1) development of a shear fatigue testing procedure capable of assessing strain energy density per cycle in a pure shear stress state and (2) incorporation of an energy-based fatigue life calculation scheme to determine the remaining fatigue life of in-service gas turbine materials subjected to pure shear fatigue.

scholarly journals Research on low cycle fatigue life prediction considering average strain

2022 ◽  
Author(s):  
Yan Peng ◽  
Yang Liu ◽  
Haoran Li ◽  
Jiankang Xing
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Damage Mechanics ◽  
Prediction Models ◽  
Low Cycle Fatigue ◽  
Prediction Method ◽  
Fatigue Life Prediction ◽  
Model Parameters ◽  
Cycle Fatigue ◽  
Average Strain

Abstract To address the difficult problems in the study of the effect of average strain on fatigue life under low-cycle fatigue loads, the effect of average strain on the low-cycle fatigue life of materials under different strain cycle ratios was discussed based on the framework of damage mechanics and its irreversible thermodynamics. By introducing the Ramberg-Osgood cyclic constitutive equation, a new low-cycle fatigue life prediction method based on the intrinsic damage dissipation theory considering average strain was proposed, which revealed the correlation between low-cycle fatigue strain life , material properties, and average strain. Through the analysis of the low-cycle fatigue test data of five different metal materials, the model parameters of the corresponding materials were obtained. The calculation results indicate that the proposed life prediction method is in good agreement with the test, and a reasonable characterization of the low-cycle fatigue life under the influence of average strain is realized. Comparing calculations with three typical low-cycle fatigue life prediction models, the new method is within two times the error band, and the prediction effect is significantly better than the existing models, which is more suitable for low-cycle fatigue life prediction. The low-cycle fatigue life prediction of different cyclic strain ratios based on the critical region intrinsic damage dissipation power method provides a new idea for the research of low-cycle fatigue life prediction of metallic materials.

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