scholarly journals Review on fatigue life assessment methods for welded joints in orthotropic steel decks of long-span bridges

2021 ◽  
Vol 1201 (1) ◽  
pp. 012036
Author(s):  
B Villoria ◽  
S C Siriwardane ◽  
H G Lemu
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Assessment Methods ◽  
Machine Learning Algorithms ◽  
Life Assessment ◽  
Steel Bridge ◽  
Long Span Bridges ◽  
Long Span ◽  
Fatigue Life Assessment ◽  
Orthotropic Steel Decks

Abstract Orthotropic Steel Decks have been used in long-span bridges for several decades because of their high capacity to weight ratio. However, many fatigue related issues have been reported. This paper provides an overview of the main existing fatigue prediction models and discusses their relevance for the fatigue life assessment of Orthotropic Steel Bridge Decks (OSBDs). Several case studies have proven the importance of considering the combined effect of wind and traffic loadings to estimate the fatigue life of long-span bridges. The importance of incorporating welding residual stresses is also well documented while it is often disregarded in design practices. Reliability-based fatigue assessment methods make it possible to quantify how the sources of uncertainty related to loading conditions, welding residual stresses or fabrication defects can affect the fatigue reliability of OSBDs. Monte Carlo simulations are often used to perform probabilistic analyses, but machine-learning algorithms are very promising and computationally efficient. The shortcomings of the Palmgren-Miner rule are discussed and the need for alternative damage accumulation indexes is clear. A number of conclusions are drawn from the analysis of fatigue tests conducted on OSBDs.

Proposal for a Total Fatigue Life Assessment Methodology That Predicts Fatigue Life From Defect Initiation to Through Wall Leak

2020 ◽  
Author(s):  
Joseph Batten ◽  
Chris Currie ◽  
Jonathan Mann ◽  
Andrew Morley
Keyword(s):  
Fatigue Life ◽  
Effective Strain ◽  
Strain Range ◽  
Assessment Methods ◽  
Life Assessment ◽  
Assessment Methodology ◽  
Traditional Assessment ◽  
Fatigue Life Assessment ◽  
Definition Of

Abstract Even with improvements to remove excessive conservatisms, current fatigue assessment approaches can result in high Cumulative Usage Factors (CUFs) for some analyses. In order to improve plant availability from these assessments and mitigate future changes to design codes, an improvement in understanding in this area is desirable. Hence the proposal for a Life Assessment Methodology (LAM) was created. The LAM is a concept for an approach based on modelling each stage of fatigue life to predict total fatigue life, as a means of minimising conservatism in an assessment, where necessary. It should also be capable of incorporating statistical methods to assign reliability figures to calculated plant lives. This paper describes the proposed definition of the LAM and how a proof of concept version of the LAM was developed to assess the Bettis Bechtel Stepped Pipe (BBSP) test. The results were presented with two seeded cases (fixed inputs) and a range of lives corresponding to associated Target Reliabilities (TRs). The Best Estimate (BE) and TR associated lives produced were based on using the latest methods available for calculating Fatigue Initiation (FI) and Fatigue Crack Growth (FCG), whereas the seeded Effective Strain Range (ESR) comparison case used current deterministic assessment methods. The results for the case study concluded that there is a benefit to pursuing the development of the LAM when compared to traditional assessment methods. It highlighted and quantified the conservatism present in traditional assessment methods for these cases as well as the need to understand the required TR for a specific component as this can have a large effect on the predicted life. With further refinements to the method, a more realistic and robust output of the total fatigue life distribution (for specific cases) would be obtained, which in turn would allow us to better quantify the conservatism associated with a TR.

Fatigue life assessment methods for railway vehicle bogie frames

2020 ◽  
Vol 116 ◽  
pp. 104725
Author(s):  
Ruixian Xiu ◽  
Maksym Spiryagin ◽  
Qing Wu ◽  
Shuchen Yang ◽  
Yanwen Liu
Keyword(s):  
Fatigue Life ◽  
Assessment Methods ◽  
Life Assessment ◽  
Railway Vehicle ◽  
Fatigue Life Assessment

Fatigue Life Assessment of Fillet Welded Joint Considering the Relaxation and Redistribution of Residual Stresses

2004 ◽  
Author(s):  
Chang Doo Jang ◽  
Ha Cheol Song ◽  
Young Chun Jo
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Crack Propagation ◽  
Welded Joint ◽  
Life Assessment ◽  
Ship Structure ◽  
Fatigue Life Assessment ◽  
Plastic Analysis

This paper presents the fatigue life assessment procedure for the welded joint of ship structure. Test model is a boxing fillet specimen, the idealized welded joint model of longitudinal and transverse members in ship structure. Fatigue test was executed according to the 14-points S-N method of JSME, and experimental data were presented in the S-N curve based on HSS (Hot Spot Stress) approach. To define the fatigue life of crack initiation and crack propagation, S-N data for each length of crack were appraised. In this study, the new FE analysis algorithms for the estimation of residual stress relaxation due to external load and residual stress redistribution due to crack propagation were proposed to assess the effect of residual stresses on crack growth precisely. Initial welding residual stress field was obtained by thermal elasto-plastic analysis considering temperature dependent material properties, and the amount of residual stress relaxation and redistribution were assessed by subsequent elasto-plastic analysis. In the analysis of crack propagation, the SIF (Stress Intensity Factor) range was evaluated by 1/4-point displacement extrapolation method, and the effect of welding residual stresses on fatigue behaviors was considered by introducing the effective SIF concept. The test results of crack propagations were compared with the predicted data from the analysis.

scholarly journals Numerical Simulation of Fatigue Performance of Diaphragm of Large-Span Bridge Orthotropic Deck

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-19
Author(s):  
Hui Li ◽  
Bo Zhao ◽  
Han Zhu
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Fatigue Life ◽  
Finite Element Model ◽  
Element Model ◽  
Life Assessment ◽  
Steel Bridge ◽  
Large Span ◽  
Finite Element Software ◽  
Fatigue Life Assessment

Under traffic loads, orthotropic steel bridge slabs suffer from an obvious fatigue problem. In particular, fatigue cracking of diaphragms seriously affects application and development of orthotropic bridge slabs. In the paper, based on cracking status quo of an orthotropic deck diaphragm of a large-span bridge, experimental tests were formulated to test stress distribution states of the diaphragm. The finite element software ABAQUS was used to establish a finite element model of the orthotropic deck diaphragm; numerical simulation was conducted on the basis of the experiments. Simulation results were compared with experimental results, so correctness of the finite element model was verified. Finally, Local Strain Approach (LSA) and Theory of Critical Distance (TCD) were used to conduct life assessment of the orthotropic deck diaphragms, and applicability of two methods was discussed. In this way, a fatigue life assessment method with high accuracy and good operability was provided for fatigue life assessment of orthotropic deck diaphragms.

Master S-N Curve-Based Fatigue Life Assessment of Steel Bridges Using Finite Element Model and Field Monitoring Data

2018 ◽  
Vol 19 (01) ◽  
pp. 1940013 ◽  
Author(s):  
X. W. Ye ◽  
Y. H. Su ◽  
T. Jin ◽  
B. Chen ◽  
J. P. Han
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Welded Joint ◽  
Element Model ◽  
Field Monitoring ◽  
Life Assessment ◽  
Monitoring Data ◽  
Steel Bridge ◽  
Structural Stress ◽  
Fatigue Life Assessment

The accuracy of fatigue life assessment for the welded joint in a steel bridge is largely dependent on an appropriate [Formula: see text]-[Formula: see text] curve. In this paper, a master [Formula: see text]-[Formula: see text] curve-based fatigue life assessment approach for the welded joint with an open-rib in orthotropic steel bridge deck is proposed based on the finite element model (FEM) and field monitoring data from structural health monitoring (SHM) system. The case studies on fatigue life assessment by use of finite element analysis (FEA) for constant-amplitude cyclic loading mode and field monitoring data under variable-amplitude cyclic loading mode are addressed. In the case of FEA, the distribution of structural stress at fatigue-prone weld toe is achieved using 4-node shell element model and then transformed into equivalent structural stress by fracture mechanics theory. The fatigue life of the welded joint is estimated with a single master [Formula: see text]-[Formula: see text] curve in the form of equivalent structural stress range versus the cycles to failure. In the case of monitoring data-based fatigue life assessment, the daily history of structural stress at diaphragm to U-rib is derived from the raw strain data measured by the instrumented fiber Bragg grating (FBG) sensors and transformed into equivalent structural stress. The fatigue life of the investigated welded joint is calculated by cyclic counting method and Palmgren–Miner linear damage cumulative rule. The master [Formula: see text]-[Formula: see text] curve method provides an effective fatigue life assessment process, especially when the nominal stress is hard to be defined. A single master [Formula: see text]-[Formula: see text] curve will facilitate to solve the difficulty in choosing a proper [Formula: see text]-[Formula: see text] curve which is required in the traditional fatigue life assessment methods.

Assessment of reliable fatigue life of orthotropic steel deck

2011 ◽  
Vol 1 (3) ◽  
Author(s):  
Ivan Lukačević ◽  
Boris Androić ◽  
Darko Dujmović
Keyword(s):  
Fatigue Life ◽  
Highway Bridges ◽  
Working Life ◽  
Life Assessment ◽  
Load Model ◽  
Reliability Indices ◽  
Load Models ◽  
Fatigue Life Assessment ◽  
Orthotropic Steel Decks ◽  
Steel Deck

AbstractThe fatigue life assessment of orthotropic steel decks of highway bridges still hasn’t been sufficiently investigated. The inspection results of orthotropic steel decks have shown that their working life can be shorter than other members of steel highway bridges due to fatigue. This means that particular details of orthotropic decks can be critical regarding the service life of a bridge. The fatigue life of typical details of orthotropic steel decks for the real load models in Croatia and for the standardized load model of highway bridges in Eurocode has been analysed. The reliability indices have also been calculated for these details and they have been used to determine reliable fatigue life. The paper proposed the introduction of the reliable fatigue life concept which is not explicitly specified in the modern standards for structures. This concept has been offered as well as the guidelines for further probabilistic research on reliable fatigue life.

scholarly journals Estimation of Fatigue Life of Long-Span Bridge by Considering Vehicle- Bridge Coupled Vibration

2015 ◽  
Vol 9 (1) ◽  
pp. 944-949
Author(s):  
Ling Jiao
Keyword(s):  
Fatigue Life ◽  
Scale Model ◽  
Steel Bridge ◽  
Coupled Vibration ◽  
Long Span Bridges ◽  
Multi Scale ◽  
Long Span ◽  
Analysis Process ◽  
Long Span Bridge ◽  
Orthotropic Steel Bridge Deck

To estimate the fatigue life of long-span steel bridge more accurately, this paper proposes a method for estimating the fatigue life of long-span bridges by considering vehicle-bridge coupled vibration. Firstly, the universal equation of vehicle-bridge vibration is derived based on triaxial standard multi-scale model of fatigue vehicle and bridge, and relevant program for vehicle-bridge coupled vibration is programmed. Secondly, a method for estimating the fatigue life of long-span steel bridge is proposed based on fracture mechanics theories, and the analysis process is expounded in details. Finally, the method for estimating fatigue life proposed in this paper is verified by taking a double pylon cablestayed bridge with orthotropic steel bridge deck slab as an example.

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