scholarly journals Based on the Fatigue Life of Welded Structures and Welding Process Design Integration

2014 ◽  
Vol 04 (06) ◽  
pp. 113-117
Author(s):  
永生 黄
Keyword(s):  
Fatigue Life ◽  
Process Design ◽  
Welding Process ◽  
Welded Structures ◽  
Design Integration

Fatigue life assessment of welded structures based on fracture mechanics

2015 ◽  
Vol 6 (1) ◽  
pp. 2-25
Author(s):  
A. Krasovskyy ◽  
A. Virta
Keyword(s):  
Fatigue Life ◽  
Fracture Mechanics ◽  
Welded Joints ◽  
Welding Process ◽  
Life Assessment ◽  
Lifetime Estimation ◽  
Worst Case ◽  
Welded Structures ◽  
Content Type ◽  
Fatigue Life Assessment

Purpose – Even though modern welding technology has improved, initial defects on weld notches cannot be avoided. Assuming the existence of crack-like flaws after the welding process, the stage of a fatigue crack nucleation becomes insignificant and the threshold for the initial crack propagation can be used as a criterion for very high cycle fatigue whereas crack growth analysis can be applied for the lifetime estimation at lower number of cycles. The purpose of this paper is to present a mechanism based approach for lifetime estimation of welded joints, subjected to a multiaxial non-proportional loading. Design/methodology/approach – The proposed method, which is based on the welding process simulation, thermophysical material modeling and fracture mechanics, considers the most important aspects for fatigue of welds. Applying worst-case assumptions, fatigue limits derived by the weight function method can be then used for the fatigue assessment of complex welded structures. Findings – An accurate mechanism based method for the fatigue life assessment of welded joints has been presented and validated. Originality/value – Compared to the fatigue limits provided by design codes, the proposed method offers more accurate lifetime estimation, a better understanding of interactions between welding process and fatigue behavior. It gives more possibilities to optimize the welding process specifically for the considered material, weld type and loading in order to achieve the full cost and weight optimization potential for industrial applications.

Fatigue life prediction of repaired welded structures

1994 ◽  
Vol 28 (2) ◽  
pp. 187-195 ◽  
Author(s):  
J.T.P. Castro ◽  
J.L.F. Freire ◽  
R.D. Vieira
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Welded Structures

scholarly journals Predicting Welding Distortion in a Panel Structure with Longitudinal Stiffeners Using Inherent Deformations Obtained by Inverse Analysis Method

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Liang ◽  
Hidekazu Murakawa
Keyword(s):  
Inverse Analysis ◽  
Welding Process ◽  
Strain Theory ◽  
The Other ◽  
Welding Distortion ◽  
Welding Deformation ◽  
Welded Structures ◽  
Longitudinal Stiffeners ◽  
Manufacturing Accuracy ◽  
Inherent Strain

Welding-induced deformation not only negatively affects dimension accuracy but also degrades the performance of product. If welding deformation can be accurately predicted beforehand, the predictions will be helpful for finding effective methods to improve manufacturing accuracy. Till now, there are two kinds of finite element method (FEM) which can be used to simulate welding deformation. One is the thermal elastic plastic FEM and the other is elastic FEM based on inherent strain theory. The former only can be used to calculate welding deformation for small or medium scale welded structures due to the limitation of computing speed. On the other hand, the latter is an effective method to estimate the total welding distortion for large and complex welded structures even though it neglects the detailed welding process. When the elastic FEM is used to calculate the welding-induced deformation for a large structure, the inherent deformations in each typical joint should be obtained beforehand. In this paper, a new method based on inverse analysis was proposed to obtain the inherent deformations for weld joints. Through introducing the inherent deformations obtained by the proposed method into the elastic FEM based on inherent strain theory, we predicted the welding deformation of a panel structure with two longitudinal stiffeners. In addition, experiments were carried out to verify the simulation results.

scholarly journals Process Knowledge Graph Modeling Techniques and Application Methods for Ship Heterogeneous Models

2021 ◽  
Author(s):  
Jinfeng Liu ◽  
Jianwei Dong ◽  
Xuwen Jing ◽  
Xuwu Cao ◽  
Chenxiao Du ◽  
...  
Keyword(s):  
Process Design ◽  
Welding Process ◽  
Mapping Method ◽  
Knowledge Graph ◽  
Case Based Reasoning ◽  
Test Model ◽  
Process Knowledge ◽  
Heterogeneous Model ◽  
Heterogeneous Models ◽  
Component Assembly

Abstract In the process design and reuse of marine component products, there are a lot of heterogeneous models, causing the problem that the process knowledge and process design experience contained in them are difficult to express and reuse. Therefore, a process knowledge representation model for ship heterogeneous model is proposed in this paper. Firstly, the multi-element process knowledge graph is constructed, and the heterogeneous ship model is described in a unified way. Then, the multi-strategy ontology mapping method is applied, and the semantic expression between the process knowledge graph and the entity model is realized. Finally, by obtaining implicit semantics based on case-based reasoning and checking the similarity of the matching results, the case knowledge reuse is achieved, to achieve rapid design of the process. This method provides reliable technical support for the design of ship component assembly and welding process, greatly shortens the design cycle, and improves the working efficiency. In addition, a case study of the test model is carried out to verify the feasibility and efficiency of the proposed method.

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