Effect of Forging Force on Fatigue Behavior of Spot Welded Joints of Aluminum Alloy 5182

2006 ◽  
Vol 129 (1) ◽  
pp. 95-100 ◽  
Author(s):  
B. H. Chang ◽  
D. Du ◽  
B. Sui ◽  
Y. Zhou ◽  
Z. Wang ◽  
...  

Using experimental and finite element analysis methods, the effects of electrode forging force are investigated on fatigue behavior and residual stress of spot welded joints of aluminum alloy 5182. Results show that applying forging force significantly reduces the residual stresses in the heat affected zone and the fatigue cracks no longer initiate from there; instead, all cracks begin from the nugget edge. In addition, the mitigation of residual stress by forging force decreases the driving force for crack propagation and leads to longer fatigue life. It can be concluded that applying forging force appropriately has a positive effect on the fatigue strength of resistance spot welded joints.

2008 ◽  
Vol 580-582 ◽  
pp. 625-628
Author(s):  
Bok Kyu Lim ◽  
Min Gun Kim ◽  
Ku Hyun Chung ◽  
Dong Youl Kim ◽  
Young Woo Choi

The stability of plate structure is a very critical problem. The spot welding is practically designed by experiential decisions; so, it is inefficient and risks fatigue fracture. In real structure, multi-spot welded joints are more frequently used than single-spot welded joint. The fatigue behavior of multi-spot welded joints is different from that of single-spot welded joints. The fatigue lives of spot-welding specimen and multi points spot-welding structure are predicted using a FEMFAT 4.4e based on the linear finite element analysis. It is necessary to establish a reasonable and systematic design criterion for the long life design of the spot-welding body structure. In this study, relative location of spot welding was chosen as parameter and the stress distribution around the spot-welding joints’ subjected tensile load was numerically analyzed.


2005 ◽  
Author(s):  
◽  
Xin Long

This dissertation presents the finite element based prediction of residual stress generation in a spot welded joint during the spot welding process and the effects of residual stress on fatigue behavior of a spot welded joint. Spot welded advanced high strength steels, namely dual phase DP600 GI and transformation induced plasticity TRIP600 steels were investigated for their fatigue life, microstructure changes and fatigue fracture mechanisms to develop design data for possible application in future light weight and more fuel efficiency automobiles.


2018 ◽  
Vol 252 ◽  
pp. 69-80 ◽  
Author(s):  
W.Y. Li ◽  
Q. Chu ◽  
X.W. Yang ◽  
J.J. Shen ◽  
A. Vairis ◽  
...  

Author(s):  
Nur Syahroni ◽  
Stig Berge

Residual stress may have a significant effect on the fatigue strength of welded joints. As a non-fluctuating stress, it has an effect similar to that of the mean stress. Recently the International Association of Ship Classification Societies (IACS) has issued Common Structural Rules (CSR) for respectively tankers (IACS 2006a) and bulk carriers (IACS 2006b). The effect of mean stress in fatigue design is taken into account in both sets of rules. However, the treatment is quite different, in particular with regard to residual stress and shakedown effects. In the present paper a comparative study of fatigue design procedures of the IACS rules is reported, with emphasis on residual stress effects. Testing was carried out with longitudinal attachment welds in the as-welded condition. The initial residual stress was measured by a sectioning method using strain gages. Hot spot stress was determined experimentally by strain gauges and numerically by finite element analysis using different types of elements. Fatigue testing was carried out and SN-curves were plotted according to the relevant stress as specified by the rules. In order to investigate the shake-down effect of residual stress, testing was performed for several pre-load conditions which could be taken to represent maximum load levels in a load history. The aim of the study is to contribute towards better understanding of the effect of residual stress and shakedown on fatigue strength of welded joints.


2011 ◽  
Vol 399-401 ◽  
pp. 2040-2043 ◽  
Author(s):  
Da Li ◽  
Hua Ji ◽  
Yan Liu ◽  
Guo Qing Gou ◽  
Hui Chen ◽  
...  

MIG welding and laser-MIG hybrid welding have been widely used to joint aluminum alloy in recent years. Residual stress and heat cycling of MIG welding and laser-MIG hybrid welding are analyzed by SYSWELD software. The results show that the peak values of the stress in hybrid welding is 30~50% less than the results in the MIG welded joints.


Author(s):  
Shivdayal Patel ◽  
B. P. Patel ◽  
Suhail Ahmad

Welding is one of the most used joining methods in the ship industry. However, residual stresses are induced in the welded joints due to the rapid heating and cooling leading to inhomogenously distributed dimensional changes and non-uniform plastic and thermal strains. A number of factors, such as welding speed, boundary conditions, weld geometry, weld thickness, welding current/voltage, number of weld passes, pre-/post-heating etc, influence the residual stress distribution. The main aim of this work is to estimate the residual stresses in welded joints through finite element analysis and to investigate the effects of boundary conditions, welding speed and plate thickness on through the thickness/surface distributions of residual stresses. The welding process is simulated using 3D Finite element model in ABAQUS FE software in two steps: 1. Transient thermal analysis and 2. Quasi-static thermo-elasto-plastic analysis. The normal residual stresses along and across the weld in the weld tow region are found to be significant with nonlinear distribution. The residual stresses increase with the increase in the thickness of the plates being welded. The nature of the normal residual stress along the weld is found to be tensile-compressive-tensile and the nature of normal residual stress across the weld is found to be tensile along the thickness direction.


2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Sha Xu ◽  
Hao Chen ◽  
Yali Yang ◽  
Kun Gao

Abstract Three-dimensional (3D) reconstruction and finite element method are combined to study the damage behavior of aluminum alloy resistance spot-welded joints. Fatigue damage of spot-welded joints under different cyclic loading stages was obtained by X-ray microcomputed tomography (X-ray micro CT). Then, avizo software was used to reconstruct the scanned data of joints with different damage degrees, and the distribution and variation of defects in the joints are obtained. On this basis, 3D finite element damage models were established. Finite element calculations were carried out to analyze the fatigue damage of spot-welded joints by adopting the effective elastic modulus as the damage parameter. The results show that the effective elastic modulus is consistent with the experimental results. The method of combining 3D reconstruction with the finite element method can be used to evaluate the internal damage of spot-welded joints and provide theoretical basis for the prediction of fatigue life.


2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940032 ◽  
Author(s):  
Pengfei Zhu ◽  
Guoqing Gou ◽  
Zhaofu Li ◽  
Minhao Zhu ◽  
Zhongyin Zhu ◽  
...  

The welding residual stress has different effects on the mechanical properties of aluminum alloy welded joints, such as size stability, fatigue strength and stress corrosion cracking. Therefore, it is very important to evaluate the welding residual stress accurately. In this paper, the residual stress of A7N01 aluminum alloy welded joints was measured by X-ray diffraction. In contrast to the traditional method, the cos[Formula: see text] method was used in this paper, the results were compared with those obtained by the conventional [Formula: see text] method. In addition, the influence of oscillation unit on the test results of the cos[Formula: see text] method was studied.


Sign in / Sign up

Export Citation Format

Share Document