The Design Master S-N Curve in ASME Div 2 Rewrite and its Validations

Dong, Ping; Prager, Martin; Osage, David A.

doi:10.1007/bf03266573

Cited by 43 publications

(37 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, it needs a fine mesh to achieve more accurate results due to its mesh sensitivity, and it is difficult to establish a uniform hot spot extrapolation formula for different weld toe types. The equivalent structural stress approach was proposed by Dong et al [13,14], and is mesh insensitive. That is, accurate results can be obtained using a coarser mesh, and computational efficiency is improved.…”

Section: Appl Sci 2019 9 X For Peer Review 2 Of 25mentioning

confidence: 99%

“…That is, accurate results can be obtained using a coarser mesh, and computational efficiency is improved. Moreover, for different weld joint types, a unified master S-N curve stress can be used for fatigue life evaluation [13]. To calculate the structural stresses, for the shell elements, Dong et al provided an approach based on the nodal force [14].…”

Section: Appl Sci 2019 9 X For Peer Review 2 Of 25mentioning

confidence: 99%

“…There are three parameters in the formula of the stress integration approach: The plate thickness, the isolation body width, and the distance between the crack propagation surface and the reference surface. Understanding of the influence of the deck thickness on fatigue life was provided by Dong et al [13]. However, the influences of the other two parameters have not been given in previous studies.…”

Section: Appl Sci 2019 9 X For Peer Review 2 Of 25mentioning

confidence: 99%

See 2 more Smart Citations

Influence of Weld Parameters on the Fatigue Life of Deck-Rib Welding Details in Orthotropic Steel Decks Based on the Improved Stress Integration Approach

et al. 2019

View full text Add to dashboard Cite

Fatigue cracks in orthotropic steel decks (OSDs) have been a serious problem of steel bridges for a long time. The structural stress approach is an important approach for fatigue life evaluation of welded structures. Firstly, two parameters and the mesh sensitivity of the stress-based integration equivalent structural stress approach (stress integration approach for short) are analyzed in this paper. Then, the applicability of the master S-N curve is verified based on experimental data of the deck-rib welding details in OSDs. Finally, the multi-scale finite element model (FEM) of Jiangyin Bridge is established, and the bridge fatigue life calculation steps based on the stress integration approach are given. The influence of the slope of the master S-N curve at high cycles on the bridge fatigue life is discussed. Further, the weld parameter influences on the bridge fatigue life are analyzed, as including the following: (1) The determination of the influence of the weld size changes caused by weld manufacturing errors on the bridge fatigue life; (2) the proposal of a new grinding treatment type, and the analysis of influence of the grinding radius on fatigue life; and (3) a comparison of the fatigue life of the deck-rib welding details under 80% partial penetration and 100% full penetration. The results show that the structural stress calculated by the stress integration approach does not change significantly with the parameters of the isolation body width w and the distance δ between the crack propagation surface and the reference surface. To simplify the calculation, δ is set as 0, and w can be set as the mesh size along the weld length direction. The mesh size of the stress integration approach is recommended as 0.25 times the deck thickness. The slope of the master S-N curve at high cycles significantly affects the bridge fatigue life, and a slope of 5 is reasonable. The weld parameter studies for the deck-rib welding details in the OSD of Jiangyin Bridge show that the change of weld size caused by manufacturing errors can obviously affect the bridge fatigue life, and the fatigue life of five different weld types varies from 51 years to 113 years. The new grinding treatment type, without weakening the deck, is beneficial to improving the bridge fatigue life. The fatigue life increases by approximately 5% with an increase of the grinding radius of 2 mm. The fatigue life of 80% partial penetration is slightly higher than that of 100% full penetration.

show abstract

Section: Appl Sci 2019 9 X For Peer Review 2 Of 25mentioning

confidence: 99%

Section: Appl Sci 2019 9 X For Peer Review 2 Of 25mentioning

confidence: 99%

Section: Appl Sci 2019 9 X For Peer Review 2 Of 25mentioning

confidence: 99%

See 1 more Smart Citation

Influence of Weld Parameters on the Fatigue Life of Deck-Rib Welding Details in Orthotropic Steel Decks Based on the Improved Stress Integration Approach

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Due to the mesh insensitivity of structural stress calculations, the higher accuracy of fatigue life prediction and the wide applicability, the nodal force-based structural stress method is one of the most notable fatigue life evaluation methods for welded structures. Dong reprocessed thousands of fatigue test data of steel welded joints from the last 50 years [7]. The research results indicated that when taking into account the influences of…”

Section: Introductionmentioning

confidence: 99%

An Entropy-Based Neighborhood Rough Set and PSO-SVRM Model for Fatigue Life Prediction of Titanium Alloy Welded Joints

Zou

Sun

Yang

2019

Entropy

View full text Add to dashboard Cite

In order to obtain comprehensive assessment of the factors influencing fatigue life and to further improve the accuracy of fatigue life prediction of welded joints, soft computing methods, including entropy-based neighborhood rough set reduction algorithm, the particle swarm optimization (PSO) algorithm and support vector regression machine (SVRM) are combined to construct a fatigue life prediction model of titanium alloy welded joints. By using an entropy-based neighborhood rough set reduction algorithm, the influencing factors of the fatigue life of titanium alloy welded joints such as joint type, plate thickness, etc. are analyzed and the reduction results are obtained. Fatigue characteristic domains are proposed and determined subsequently according to the reduction results. The PSO-SVRM model for fatigue life prediction of titanium alloy welded joints is established in the suggested fatigue characteristic domains. Experimental results show that by taking into account the impact of joint type, the PSO-SVRM model could better predict the fatigue life of titanium alloy welded joints. The PSO-SVRM model indicates the relationship between fatigue life and fatigue life influencing factors in multidimensional space compared with the conventional least-square S-N curve fitting method, it could predict the fatigue life of the titanium alloy welded joints more accurately thus helps to the reliability design of the structure. joint thickness and load model, the S-N sample data is compressed into a narrow band. In the present study, comprehensive and quantitative analysis of the influencing factors which affect the fatigue life of welded joints is lacking and the problem of low precision of fatigue life prediction of welded joints still exists.Thermodynamics entropy has been used for fatigue life prediction for a long time. For example, a damage metric based on the second law of thermodynamics and statistical mechanics was presented [8]. The proposed thermodynamic framework treated a solid body as a thermodynamic system and required that the entropy production be non-negative. A thermodynamic framework was presented for damage mechanics of solid materials [9]. It was believed that there was no need for physically meaningless empirical parameters to define a phenomenological damage potential surface or a Weibull function to trace damage evolution in solid continuum. A generalized theory of evolution based on the concept of tribo-fatigue entropy was proposed where tribo-fatigue entropy was determined by the processes of damage ability conditioned by thermodynamic and mechanical effects causing to the change of states of any systems [10]. The Shannon's differential entropies of both distributions of the strain in the loading direction and the first principal strain were employed at the tension peak of the cycles as measuring parameters of strain inhomogeneity [11]. A thermo-mechanical fatigue life prediction model based on the theory of damage mechanics was presented in [12]. The damage evolution, corresponding to the mate...

show abstract

“…The master S-N curve for fatigue design based on equivalent structural stress range is determined by linear regression analysis. Statistical results show that the scatter level of all S-N samples represented by standard deviations is about 0.25 [8]. In order to further reduce the scatter degree of S-N curves and to improve the fatigue life prediction accuracy, rough set theory is used for analysis of the factors which influence the fatigue life of the aluminum alloy welded joints.…”

Section: Introductionmentioning

confidence: 99%

Fatigue life prediction of 5083 and 5A06 aluminum alloy T-welded joints based on the fatigue characteristics domain

Zou

Yang

Tan

et al. 2018

Frattura Ed Integrità Strutturale

View full text Add to dashboard Cite

ABSTRACT. Three-point bending fatigue test of 5083 and 5A06 aluminum alloy T-welded joints is carried out, and the fatigue life of the specimens with different influencing factors are obtained. Finite element model of the Twelded joint is established and the nodal force based structural stress is calculated. Neighborhood rough set theory is used for analysis of the factors which influence the fatigue life of the aluminum alloy welded joints. Key influencing factors are studied and the fatigue characteristic domains are determined. The master S-N curve characterized by the nodal force based structural stress range and cycles to failure on bi-logarithmic coordinate as well as S-N curves corresponding to the fatigue characteristic domain are fitted. A case study of fatigue life prediction of 5A06 aluminum alloy welded joint indicates the effectiveness of the fatigue life prediction method based on the fatigue characteristic domain.

show abstract

The Design Master S-N Curve in ASME Div 2 Rewrite and its Validations

Cited by 43 publications

References 8 publications

Influence of Weld Parameters on the Fatigue Life of Deck-Rib Welding Details in Orthotropic Steel Decks Based on the Improved Stress Integration Approach

Influence of Weld Parameters on the Fatigue Life of Deck-Rib Welding Details in Orthotropic Steel Decks Based on the Improved Stress Integration Approach

An Entropy-Based Neighborhood Rough Set and PSO-SVRM Model for Fatigue Life Prediction of Titanium Alloy Welded Joints

Fatigue life prediction of 5083 and 5A06 aluminum alloy T-welded joints based on the fatigue characteristics domain

Contact Info

Product

Resources

About