A Simplified Transient Thermal Analysis of Resistance Spot Welding Process

2010 ◽  
Vol 154-155 ◽  
pp. 443-446
Author(s):  
Zhi Gang Hou ◽  
Jun Zhao ◽  
Li Qiang Xu ◽  
Zhong Guo
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Complex Structure ◽  
Welding Process ◽  
Temperature Dependent ◽  
Resistance Spot ◽  
Whole Process ◽  
History Of ◽  
Transient Thermal

In order to theoretically simulate the welding process of complex structure with large quantities of welding spots, a simplified method for analyzing a single spot welding should be developed firstly. In this paper, a 2D axisymmetric model of thermoelectric Finite Element Method (FEM) is developed to analyze the transient thermal behavior of Resistance Spot Welding (RSW) process using ANSYS. The determination of the contact resistance at the faying surface is moderately simplified to reduce the calculating time, while the temperature dependent material properties, phase change and convectional boundary conditions are taken into account for the improvement of the calculated accuracy. The thermal history of the whole process and temperature distributions for any position in the weldment is obtained through the analysis. The model can also predict the weld nugget size and the width of the Heat Affected Zone (HAZ).

Numerical Analysis of Transport Phenomena in Resistance Spot Welding Process

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
YongBing Li ◽  
ZhongQin Lin ◽  
Qi Shen ◽  
XinMin Lai
Keyword(s):  
Mass Transport ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Weld Nugget ◽  
Temperature Dependent ◽  
Resistance Spot ◽  
Nugget Formation ◽  
Thermal Fluid Flow ◽  
Transport Laws

Resistance spot welding (RSW) is a very complicated process involving electromagnetic, thermal, fluid flow, mechanical, and metallurgical variables. Since weld nugget area is closed and unobservable using experimental means, numerical methods are generally used to reveal the nugget formation mechanism. Traditional RSW models focus on the electrothermal behaviors in the nugget and do not have the ability to model mass transport caused by induced magnetic forces in the molten nugget. In this paper, a multiphysics model, which comprehensively considers the coupling of electric, magnetic, thermal, and flow fields during RSW, temperature-dependent physical properties, and phase transformation, is used to investigate the heat and mass transport laws in the weld nugget and to reveal the interaction of the heat and mass transports and their evolutions. Results showed that strong and complicated mass transport appears in the weld nugget and substantially changed the heat transport laws and, therefore, would be able to substantially affect the hardening, segregation, and residual stress of the weld. Compared with the traditional models which could not consider the mass transport, the multiphysics model proposed in this paper could simulate the RSW process with higher accuracy and more realities.

THERMOMECHANICAL ANALYSIS OF THE RESISTANCE SPOT-WELDING PROCESS

2018 ◽  
Vol 10 (5) ◽  
pp. 449-455 ◽  
Author(s):  
Habib Lebbal ◽  
Lahouari Boukhris ◽  
Habib Berrekia ◽  
Abdelkader Ziadi
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Thermomechanical Analysis ◽  
Resistance Spot

Analysis of Electromagnetic Inverse Model of Resistance Spot Welding

2010 ◽  
Vol 160-162 ◽  
pp. 974-979
Author(s):  
Nai Feng Fan ◽  
Zhen Luo ◽  
Yang Li ◽  
Wen Bo Xuan
Keyword(s):  
Resistance Spot Welding ◽  
Regularization Method ◽  
Spot Welding ◽  
Influence Factors ◽  
Great Influence ◽  
Welding Process ◽  
Inverse Model ◽  
Resistance Spot ◽  
Inversion Theory

Resistance spot welding (RSW) is an important welding process in modern industrial production, and the quality of welding nugget determines the strength of products to a large extent. Limited by the level of RSW quality monitor, however, RSW has rarely been applied to the fields with high welding quality requirements. Associated with the inversion theory, in this paper, an electromagnetic inverse model of RSW was established, and the analysis of influence factors, such as the layout of the probes, the discrete program and the regularization method, was implemented as well. The result shows that the layout of the probe and the regularization method has great influence on the model. When the probe is located at the y direction of x-axis or the x direction of y-axis and Conjugate Gradient method is selected, a much better outcome can be achieved.

Micro Hardness in the Welded Area at Resistance Spot Welding

2016 ◽  
Vol 1138 ◽  
pp. 153-158
Author(s):  
Mihai Boca ◽  
Gheorghe Nagit ◽  
Laurenţiu Slătineanu
Keyword(s):  
Mechanical Properties ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Graphical Representation ◽  
Welding Process ◽  
Electrical Current ◽  
Micro Hardness ◽  
Current Time ◽  
Resistance Spot ◽  
Welding Spot

The resistance spot welding process represents the welding technology used to obtain assemblies trough welded spots characterized by adequate mechanical properties. This assembly process is used mainly into the automotive, petroleum and naval industries. It is applied due to the significant advantages concerning the technology and service properties of the obtained assembly. This paper purposes a study concerning the micro hardness change of an assembly made by resistance welding spot. The entire process of plastic deformations together with the solidification step developed in the presence of the heat generated during welding process determines the mechanical characteristics of the welded spot and, of course, of the assembly obtained. In such conditions, depending on the changes developed during the welding process, the micro hardness of the welded spot varies between the fusion area (FA) and heat affected zone (HAZ). In this way, the graphical representation of the micro hardness repartition gives clues about the weakness areas which don’t correspond to the requirements. As input factors, in this study, the values of current intensity, the electrical current time and the force pressure were considered. In order to solve the proposed problem and to graphically highlight the variation of the micro hardness obtained for welded points, it was used a classical welding device and a micro hardness device analyzer. The graphical representation shows that the micro-hardness and, as a consequence, some mechanical properties changes in the specified region and in the entire mass of the welded spot changes. In this way, the structure of welded spot is characterized by a variation of the hardness in the interest areas.

Evolution of Interfacial Microstructure During Resistance Spot Welding of Cu and Al With Ni-P Coating

2021 ◽  
Author(s):  
Nannan Chen ◽  
Hongliang Wang ◽  
Jingjing Li ◽  
Vic Liu ◽  
James Schroth
Keyword(s):  
Heat Input ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Void Formation ◽  
Welding Process ◽  
Kirkendall Effect ◽  
Interfacial Microstructure ◽  
Formation Mechanisms ◽  
Elemental Distribution ◽  
Resistance Spot

Abstract Dissimilar materials of copper (Cu) to aluminum (Al) with nickel-phosphorus (Ni-P) coatings were joined using resistance spot welding. The Ni-P coatings were electroless plated on the Al surfaces to eliminate the formation of brittle Cu-Al intermetallic compounds (IMCs) at the faying interface between Cu and Al. Three welding schedules with various heat input were employed to produce different interfacial microstructure. The evolution of interfaces in terms of phase constitution, elemental distribution and defects (gaps and voids) was characterized and the formation mechanisms were elucidated. During the welding process, the bonding between Cu and Ni-P forms through solid-state diffusion, while the faster diffusion rate of Cu relative to Ni and P atoms promotes the generation of sub-micron voids. As the heat input increases, gaps at the Cu/Ni-P interface diminish accompanied by increase of sub-micron voids. A moderate schedule helps to remove the gaps and inhibits the void formation. An Al3Ni layer and nanovoids were found around the interface of Ni-P/Al. The increased heat input decreases the grain size of Al3Ni at the interface by eutectic remelting and increases the nanovoids by enhanced nanoscale Kirkendall effect.

Simulations of Residual Stresses in Resistance Spot Welding Process

2010 ◽  
Vol 33 (9) ◽  
pp. 843-857 ◽  
Author(s):  
R. Dalewski ◽  
J. Jachimowicz ◽  
M. Pietrzakowski
Keyword(s):  
Residual Stresses ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Resistance Spot

scholarly journals Quality Prediction of Resistance Spot Welding Joints From Pre- and Post-Welding Inputs Using Stacking of Tree Ensemble Models

2021 ◽  
Author(s):  
Óscar Martín ◽  
Virginia Ahedo ◽  
José Ignacio Santos ◽  
José Manuel Galán
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Characteristic Curve ◽  
Welding Process ◽  
Quality Level ◽  
Ensemble Models ◽  
Resistance Spot ◽  
Single Output ◽  
Combined Use ◽  
Welding Joints

Abstract Resistance spot welding (RSW) is a widespread manufacturing process in the automotive industry. There are different approaches for assessing the quality level of RSW joints. Multi-input-single-output methods, which take as inputs either the intrinsic parameters of the welding process or ultrasonic nondestructive testing variables, are commonly used. This work demonstrates that the combined use of both types of inputs can significantly improve the already competitive approach based exclusively on ultrasonic analyses. The use of stacking of tree ensemble models as classifiers dominates the classification results in terms of accuracy, F-measure and area under the receiver operating characteristic curve metrics. Through variable importance analyses, the results show that although the welding process parameters are less relevant than the ultrasonic testing variables, some of the former provide marginal information not fully captured by the latter.

Sign in / Sign up

Export Citation Format

Share Document