3D Measurement of Electrode Contact Area in Resistance Spot Welding of Coated Steel

2004 ◽  
Vol 48 (11-12) ◽  
pp. 26-30 ◽  
Author(s):  
I. Polajnar ◽  
D. Bračun ◽  
P. Podržaj ◽  
J. Diaci
Keyword(s):  
Contact Area ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Coated Steel ◽  
3D Measurement ◽  
Resistance Spot ◽  
Electrode Contact

Contact Area Modeling and On-Line Estimation in Resistance Spot Welding

Manufacturing ◽  
2002 ◽  
Author(s):  
Wei Li
Keyword(s):  
Contact Area ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Process Conditions ◽  
Electrode Wear ◽  
Welding Time ◽  
Contact Areas ◽  
Resistance Spot ◽  
On Line

Contact areas at both electrode-to-sheet and sheet-to-sheet interfaces are important in the resistance spot welding process. Given electrode force and welding time, contact areas strongly affect the amount of electrical current needed to make a good weld. In production, process variation such as electrode wear and misalignment causes the contact areas to vary. This effect contributes largely to the quality variation of resistance spot welds. This paper proposes a model-based approach to contact area estimation in the resistance spot welding process. A finite element analysis procedure is used to characterize the contact area behaviors. Based on the understanding from the simulations, a lumped parameter model, together with its calibration and estimation procedures, is developed for on-line applications. The proposed method is demonstrated successful under various process conditions including electrode size, force, welding time and current. It provides important information for on-line monitoring and control of the resistance spot welding process.

Modeling and On-Line Estimation of Electrode Wear in Resistance Spot Welding

2004 ◽  
Vol 127 (4) ◽  
pp. 709-717 ◽  
Author(s):  
Wei Li
Keyword(s):  
Contact Area ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Estimation Algorithm ◽  
Contact Condition ◽  
Electrode Wear ◽  
Resistance Spot ◽  
On Line

Electrode wear is inherent in the resistance spot welding process. It determines the electrical and mechanical contact condition and thus strongly affects the resistance spot weld quality. A practical approach to minimizing the electrode wear effect is to compensate the welding current as the electrodes wear. However, the existing methods for welding current compensation rely on either a predetermined stepper schedule or an expulsion detection algorithm. These methods are not reliable since the welding current is not determined based on the contact condition for each weld made in the welding process. This paper presents an on-line electrode wear estimation approach to determining the contact condition and the welding current needed to make every weld a good weld during the entire life of the electrodes. In the study, an incrementally coupled finite element simulation was first formulated to analyze the contact area behavior in the resistance spot welding process. A lumped parameter model was then developed to characterize the contact area change with the dynamic resistance measurement. A calibration and an estimation algorithm were subsequently devised for on-line applications. The proposed approach has been validated with experimental data. The results have shown that the estimation algorithm is robust under various process conditions including both welding current and electrode force.

Resistance Spot Welding between Copper Coated Steel and Aluminum Alloy

2014 ◽  
Vol 675-677 ◽  
pp. 19-22 ◽  
Author(s):  
Li Hu Cui ◽  
Ran Feng Qiu ◽  
Hong Xin Shi ◽  
Yao Min Zhu
Keyword(s):  
Aluminum Alloy ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Current ◽  
Middle Layer ◽  
Welding Parameters ◽  
Coated Steel ◽  
Resistance Spot ◽  
Nugget Diameter ◽  
Electrode Force

Aluminum alloy A6061 and copper coated steel was welded by resistance spot welding with. The mechanical properties of the joint were investigated; the effects of welding parameters on nugget diameter and tensile shear load of the joints were discussed. The results show that the joint strength and nugget diameter increases with the increase of welding current and welding time and decreases with the increase of electrode force. As a result, copper plating as the middle layer of resistance spot welding is suitable for welding of aluminum alloy/steel.

scholarly journals General Approach for Inline Electrode Wear Monitoring at Resistance Spot Welding

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 685
Author(s):  
Christian Mathiszik ◽  
David Köberlin ◽  
Stefan Heilmann ◽  
Jörg Zschetzsche ◽  
Uwe Füssel
Keyword(s):  
Contact Area ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Electrode Wear ◽  
Actual Process ◽  
Welding Quality ◽  
Process Data ◽  
Resistance Spot ◽  
Electrode Length ◽  
Wear Modes

Electrodes for resistance spot welding inevitably wear out. In order to extend their service life, the tip-dressing process restores their original geometry. So far, however, the point in time for tip-dressing is mainly based on experience and not on process data. Therefore, this study aims to evaluate the in-situ or inline wear during the welding process without using additional sensors, and to base the timing for tip-dressing on continuous process monitoring, extending electrode life even further. Under laboratory conditions, electrode wear is analyzed by topographical measurements deepening the knowledge of the known main wear modes of resistance-spot-welding electrodes, mushrooming and plateau forming, and characterizing an electrode length delta over the number of spot welds. In general, electrode wear results in deformation of the electrode contact area, which influences process parameters and thereby weld quality. The conducted tests show correlation between this deformed contact area and the electrode length delta. The study shows that this electrode length delta is visible in actual process data, and can therefore be used as a criterion to characterize the wear of electrodes. Furthermore, this study gives reason to question commonly used spot-welding quality criteria and suggests different approaches, such as basing spot-welding quality on the possibility of nondestructive testing.

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