The Experts below are selected from a list of 28509 Experts worldwide ranked by ideXlab platform
Yi Huang - One of the best experts on this subject based on the ideXlab platform.
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Multiaxial fatigue life prediction of tubular K-joints using an alternative Structural Stress Approach
Ocean Engineering, 2020Co-Authors: Gang Liu, Li Zhiyuan, Yi HuangAbstract:Abstract Tubular K-joints, frequently employed in offshore structures, are subjected to multiaxial Stresses. It is difficult to accurately assess fatigue strength of tubular K-joints using the uniaxial fatigue theory. In this paper, a multiaxial fatigue life prediction method for tubular K-joints is proposed, which is based on an improved Zero Point Structure Stress (ZPSS) Approach that accounts for the Stress gradient in the thickness direction to quantify the structure Stress at the weld toe of a tubular K-joint. The multiaxial fatigue life is predicted making use of the Modified Wohler Curve Method (MWCM) as the multiaxial damage criterion. It is found that the multiaxial fatigue estimation using the proposed method predicts the fatigue critical point well. Meanwhile, the estimated multiaxial fatigue lives are much closer to experimental lives, in comparison with the uniaxial fatigue estimation using the CIDECT specification.
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prediction of Stress distribution along the intersection of tubular t joints by a novel Structural Stress Approach
International Journal of Fatigue, 2015Co-Authors: Gang Liu, Xiao Ling Zhao, Yi HuangAbstract:Abstract The Zero Point Structural Stress (ZPSS) Approach is improved to calculate the Structural Stress for the fatigue life assessment of tubular joints. In the ZPSS Approach, the Stress distribution perpendicular to the Stress classification line (SCL) can be obtained directly by post-processing the finite element (FE) results. The applicability and accuracy of the Approach is verified by comparing the FE results with fatigue experimental test data. High fit degree parametric equations for Stress concentration factor calculation are derived based on the ZPSS Approach for Stress analysis of tubular T-joints in engineering.
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a novel Structural Stress Approach for multiaxial fatigue strength assessment of welded joints
International Journal of Fatigue, 2014Co-Authors: Gang Liu, Yingfang Liu, Yi HuangAbstract:Abstract A new Approach to estimate the Structural Stress for the assessment of the multiaxial fatigue strength of welded joints is proposed. In this Approach, the Structural Stress at a point just below the weld toe in the plate thickness direction is evaluated and adopted for the multiaxial fatigue strength assessment of complex welded joints in combination with the Modified Wohler Curve Method. Numerical results show that the adoption of the thus estimated Structural Stress, rather than the traditional hot spot Stress, produces more accurate fatigue life estimation for structure members experiencing either uniaxial or multiaxial loading.
Gang Liu - One of the best experts on this subject based on the ideXlab platform.
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Multiaxial fatigue life prediction of tubular K-joints using an alternative Structural Stress Approach
Ocean Engineering, 2020Co-Authors: Gang Liu, Li Zhiyuan, Yi HuangAbstract:Abstract Tubular K-joints, frequently employed in offshore structures, are subjected to multiaxial Stresses. It is difficult to accurately assess fatigue strength of tubular K-joints using the uniaxial fatigue theory. In this paper, a multiaxial fatigue life prediction method for tubular K-joints is proposed, which is based on an improved Zero Point Structure Stress (ZPSS) Approach that accounts for the Stress gradient in the thickness direction to quantify the structure Stress at the weld toe of a tubular K-joint. The multiaxial fatigue life is predicted making use of the Modified Wohler Curve Method (MWCM) as the multiaxial damage criterion. It is found that the multiaxial fatigue estimation using the proposed method predicts the fatigue critical point well. Meanwhile, the estimated multiaxial fatigue lives are much closer to experimental lives, in comparison with the uniaxial fatigue estimation using the CIDECT specification.
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prediction of Stress distribution along the intersection of tubular t joints by a novel Structural Stress Approach
International Journal of Fatigue, 2015Co-Authors: Gang Liu, Xiao Ling Zhao, Yi HuangAbstract:Abstract The Zero Point Structural Stress (ZPSS) Approach is improved to calculate the Structural Stress for the fatigue life assessment of tubular joints. In the ZPSS Approach, the Stress distribution perpendicular to the Stress classification line (SCL) can be obtained directly by post-processing the finite element (FE) results. The applicability and accuracy of the Approach is verified by comparing the FE results with fatigue experimental test data. High fit degree parametric equations for Stress concentration factor calculation are derived based on the ZPSS Approach for Stress analysis of tubular T-joints in engineering.
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a novel Structural Stress Approach for multiaxial fatigue strength assessment of welded joints
International Journal of Fatigue, 2014Co-Authors: Gang Liu, Yingfang Liu, Yi HuangAbstract:Abstract A new Approach to estimate the Structural Stress for the assessment of the multiaxial fatigue strength of welded joints is proposed. In this Approach, the Structural Stress at a point just below the weld toe in the plate thickness direction is evaluated and adopted for the multiaxial fatigue strength assessment of complex welded joints in combination with the Modified Wohler Curve Method. Numerical results show that the adoption of the thus estimated Structural Stress, rather than the traditional hot spot Stress, produces more accurate fatigue life estimation for structure members experiencing either uniaxial or multiaxial loading.
Pingsha Dong - One of the best experts on this subject based on the ideXlab platform.
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fatigue analysis of titanium welded joints using mesh insensitive Structural Stress Approach
International Conference Mechanical Materials and Manufacturing, 2011Co-Authors: Xin Hua Yang, Pingsha Dong, Rui Ming RenAbstract:Mesh-insensitive Structural Stress Approach is a robust method for fatigue characteristic analysis of welded structures and has been validated in correlating a large amount of published fatigue test of steel welded joints in the literature. Regarding Titanium welded joints, the combination of Stress states and geometric shape can also lead to Stress concentration that can result in fatigue crack initiation around the welded joints. This paper aims to analyze well-documented fatigue data of transverse and longitudinal fillet welded joints of Titanium using mesh-insensitive Structural Stress Approach. This study is the first time using the Approach for titanium fatigue data analysis. The results show that the employed method can correlate fatigue data of Titanium welded joints noticeably and make sense to understand the effect of thickness on fatigue life of the joints better than conventional methods.
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fatigue analysis of spot welds using a mesh insensitive Structural Stress Approach
International Journal of Fatigue, 2007Co-Authors: Hong Tae Kang, Pingsha Dong, J K HongAbstract:Abstract This paper describes the application procedures of a nodal force based mesh-insensitive Structural Stress parameter for analysis of a comprehensive set of spot weld fatigue test data collected from a series of advanced high strength sheet steels. The Structural Stress parameter is calculated in an equilibrium sense in terms of bending and membrane components from nodal forces and moments at each grid point along the periphery of a weld nugget. Based on fracture mechanics considerations, an equivalent Structural Stress parameter is then used to take into account the effects of loading mode and sheet thickness on the fatigue of spot welded joints. The equivalent Structural Stress is proven effective in consolidating the large amount of fatigue data of spot welds for transformation induced plasticity (TRIP), dual-phase (DP), and high strength low alloy (HSLA) steels subjected to both tensile shear and coach peel loadings. As a result, a single master S–N can be established for fatigue design and life prediction of spot-welded structures.
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Equilibrium-equivalent Structural Stress Approach to fatigue analysis of a rectangular hollow section joint
International Journal of Fatigue, 2005Co-Authors: Hiroko Kyuba, Pingsha DongAbstract:Abstract The equilibrium-equivalent Structural Stress method has been recently developed through several joint industry projects as a robust method to analyze welded components using finite element methods. This method has been proven effective in correlating a large amount of published fatigue test results in the literature. The authors employed this equilibrium-equivalent Structural Stress method for a competition organized by the SAE Fatigue Design & Evaluation (FD&E) Committee to predict the fatigue life of a rectangular hollow section joint. Among all the methods used by many participants, the authors’ life prediction was selected as the best, based on the actual test results. This paper provides the details of the SAE FD&E fatigue challenge problem definition, test results, and our Structural Stress Approach. The predicted mean life by the equilibrium-equivalent Structural Stress method utilizing the proposed ASME Div. II Structural Stress curve was in excellent agreement with the actual mean life of the experimental results. Other Stress indexes (such as the maximum principal Stress and the von Mises Stress) had maximum Stress at a location different from the actual crack location. Furthermore, the equilibrium-equivalent Structural Stress showed significant mesh tolerance with only a few percent difference in Stresses when halving the mesh size.
J K Hong - One of the best experts on this subject based on the ideXlab platform.
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Fatigue Evaluation Procedures for Multiaxial Loading in Welded Structures Using Battelle Structural Stress Approach
Volume 5: Materials Technology; Petroleum Technology, 2014Co-Authors: J K Hong, Thomas P. ForteAbstract:The Battelle Structural Stress method is examined for the evaluation of multiaxial loading fatigue behavior in welded structures. Even though the Structural Stress and its master S-N curve Approach have been mainly focused on normal loading dominant (Mode I) failure cases, the evaluations on multiaxial loading weld fatigue using Structural Stress parameters have been relatively recently performed such as using the modified Gough ellipse [1] and the path-dependent maximum range (PDMR) cycle counting procedure [2].In this article, in order to evaluate the multiaxial fatigue behavior, an effective equivalent Structural Stress range (EESS) parameter is defined as a von Mises form of combined normal and in-plane shear equivalent Structural Stress ranges. The newly developed in-plane shear equivalent Structural Stress range for in-plane shear dominant loading (Mode III) is introduced. This in-plane shear equivalent Structural Stress range parameter has been formulated based on the evaluation of fatigue behavior under in-plane shear loading. Also, the EESS parameter is a function of damage parameter based on the PDMR procedure.In this article, the procedure employing the EESS parameter is evaluated and validated using published weld fatigue data. The multiaxial fatigue date is consolidated within a small scatter band regardless of in-phase, out-of-phase, and non-proportional loading as well as torsional loading. Finally, the design master S-N curve is proposed for multiaxial loading weld fatigue.It is found that the dimensionless bend ratio parameter, Iτ (rτ)1/mτ for in-plane shear loading is a much more significant correction than that for normal loading when the ratio of bending Structural Stress to the total Structural Stress, rτ increases. This procedure will be beneficial for fatigue design with preventing over-conservatism.Copyright © 2014 by ASME
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fatigue analysis of spot welds using a mesh insensitive Structural Stress Approach
International Journal of Fatigue, 2007Co-Authors: Hong Tae Kang, Pingsha Dong, J K HongAbstract:Abstract This paper describes the application procedures of a nodal force based mesh-insensitive Structural Stress parameter for analysis of a comprehensive set of spot weld fatigue test data collected from a series of advanced high strength sheet steels. The Structural Stress parameter is calculated in an equilibrium sense in terms of bending and membrane components from nodal forces and moments at each grid point along the periphery of a weld nugget. Based on fracture mechanics considerations, an equivalent Structural Stress parameter is then used to take into account the effects of loading mode and sheet thickness on the fatigue of spot welded joints. The equivalent Structural Stress is proven effective in consolidating the large amount of fatigue data of spot welds for transformation induced plasticity (TRIP), dual-phase (DP), and high strength low alloy (HSLA) steels subjected to both tensile shear and coach peel loadings. As a result, a single master S–N can be established for fatigue design and life prediction of spot-welded structures.
Yingfang Liu - One of the best experts on this subject based on the ideXlab platform.
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a novel Structural Stress Approach for multiaxial fatigue strength assessment of welded joints
International Journal of Fatigue, 2014Co-Authors: Gang Liu, Yingfang Liu, Yi HuangAbstract:Abstract A new Approach to estimate the Structural Stress for the assessment of the multiaxial fatigue strength of welded joints is proposed. In this Approach, the Structural Stress at a point just below the weld toe in the plate thickness direction is evaluated and adopted for the multiaxial fatigue strength assessment of complex welded joints in combination with the Modified Wohler Curve Method. Numerical results show that the adoption of the thus estimated Structural Stress, rather than the traditional hot spot Stress, produces more accurate fatigue life estimation for structure members experiencing either uniaxial or multiaxial loading.
