scholarly journals Dissimilar spot welding of DQSK/DP600 steels: the weld-nugget growth

2016 ◽  
Vol 50 (5) ◽  
pp. 761-765 ◽  
Author(s):  
Seyed Pirooz Hoveida Marashi
Keyword(s):  
Spot Welding ◽  
Weld Nugget ◽  
Nugget Growth

Simulating Thermoelectric Effect and Its Impact on Asymmetric Weld Nugget Growth in Aluminum Resistance Spot Welding

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Lin Deng ◽  
YongBing Li ◽  
Wayne Cai ◽  
Amberlee S. Haselhuhn ◽  
Blair E. Carlson
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Weld Nugget ◽  
Thermoelectric Effects ◽  
Element Analysis ◽  
Resistance Spot ◽  
Seebeck Coefficients ◽  
Nugget Growth ◽  
Simulation Results ◽  
The Impact

Abstract Resistance spot welding (RSW) of aluminum–aluminum (Al–Al) is known to be very challenging, with the asymmetric growth of the weld nugget often observed. In this article, a semicoupled electrical–thermal–mechanical finite element analysis (FEA) procedure was established to simulate the RSW of two layers of AA6022-T4 sheets using a specially designed Multi-Ring Domed (MRD) electrodes. Critical to the modeling procedure was the thermoelectric (including the Peltier, Thomson, and Seebeck effects) analyses to simulate the asymmetric nugget growth in the welding stage. Key input parameters such as the Seebeck coefficients and high-temperature flow stress curves were measured. Simulation results, experimentally validated, indicated that the newly developed procedure could successfully predict the asymmetric weld nugget growth. Simulation results also showed the Seebeck effect in the holding stage. The simulations represent the first quantitative investigation of the impact of the thermoelectric effects on resistance spot welding.

Study on Nugget Growth in Resistance Spot Welding of Thin Aluminum A1100 Using Welding Simulation

2018 ◽  
Vol 929 ◽  
pp. 191-199
Author(s):  
Ario Sunar Baskoro ◽  
Andreas Edyanto ◽  
Muhammad Azwar Amat ◽  
Hakam Muzaki
Keyword(s):  
Weld Joint ◽  
Cycle Time ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Metal Plate ◽  
Weld Nugget ◽  
Welding Time ◽  
Resistance Spot ◽  
Nugget Growth

Resistance spot welding (RSW), generally which is one of the most often used to joint metal plate in the automotive and aviation industries. RSW welding process involves electrical, thermal mechanical, metallurgy, and complex surface phenomenon. Unlike the other welding processes, weld joint formation in RSW process occurs very quick (in milli-seconds) and took place between the workpieces overlap each other. Welding simulation allows visual examination of the weld joint without having to perform an expensive experiment. Weld nugget size is the most important parameter in determining the mechanical behavior of welded joints in RSW process. The quality and strength of the weld joint in RSW process is predominantly determined by the shape and size of the weld nugget. Simulation modeling of RSW process performed using ANSYS Parametric Design Language (APDL) module based on the finite element method (FEM), embedded in ANSYS Workbench. Electrical and transient-thermal interaction was developed to study the weld nugget growth on resistance spot welding of aluminum A1100 metal plate with a thickness of 0.4 mm respectively. Weld nugget diameter can be well predicted by using this simulation model from the temperature distribution during the welding process. Welding is performed by varying the weld current (1 kA and 2 kA) and the welding time for each electric current, which are start from 0.5, 1.0, and 1.5 cycle time. Nugget diameter for each of the welding parameters from the simulation modelling were 4,276 mm, 4,372 mm, 4,668 mm, 5,616 mm and 5,896 mm. Weld expulsion occurred for the specimen with welding current 2 kA and welding time 1.5 cycle time, characterized by the decreasing of the tensile-shear strength of the specimen.

Axisymmetric Nugget Growth During Resistance Spot Welding

1990 ◽  
Vol 112 (2) ◽  
pp. 309-316 ◽  
Author(s):  
P. S. Wei ◽  
C. Y. Ho
Keyword(s):  
Experimental Data ◽  
Heat Generation ◽  
Joule Heating ◽  
Spot Welding ◽  
Early Stage ◽  
Three Dimensional ◽  
Weld Nugget ◽  
Faying Surface ◽  
Nugget Growth ◽  
Radial Heat

Three-dimensional weld nugget growths for different welding currents, electrode tip shapes, and thickness ratios of workpieces are determined. By providing an effective model to estimate the heat generation at the faying surface between workpieces and taking into account the phase change due to melting, results show that the calculated weld nugget growth, nugget thickness, and shape of the nugget agree well with experimental data. Heat generation at the faying surface in the early stage of welding and joule heating at long weld times dominate the nugget growth. Consideration of radial heat loss is necessary at longer weld times and higher welding currents.

A Comparative Study of AC and MFDC Resistance Spot Welding

2004 ◽  
Author(s):  
Wei Li ◽  
Daniel Cerjanec
Keyword(s):  
Comparative Study ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Median Frequency ◽  
Resistance Spot ◽  
Secondary Voltage ◽  
Nugget Growth ◽  
Welding Processes

This paper presents a comparative study of the AC and MFDC resistance spot welding process. Two identical welders were used; one with a single phase AC and the other with a median frequency DC weld control. Both welders were instrumented such that the primary and secondary voltage and current could be collected. A nugget growth experiment was conducted to compare the weld size and energy consumption in the AC and MFDC welding processes. It is found that the MFDC process generally produces larger welds with the same welding current. However, this difference is more prominent when the welding current is low. Overall the AC welding process consumes more energy to make a same size weld. The larger the welding current is used, the less efficient the AC process becomes.

A Microscopic Approach to Determine Electrothermal Contact Conditions During Resistance Spot Welding Process

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
P. Rogeon ◽  
R. Raoelison ◽  
P. Carre ◽  
F. Dechalotte
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Electrical Contact ◽  
Welding Process ◽  
Contact Temperature ◽  
Macroscopic Model ◽  
Contact Conditions ◽  
Imperfect Contact ◽  
Resistance Spot ◽  
Nugget Growth

This study deals with resistance spot welding process modeling. Particular attention must be paid to the interfacial conditions, which strongly influence the nugget growth. Imperfect contact conditions are usually used in the macroscopic model to account for the electrical and thermal volume phenomena, which occur near a metallic interface crossed by an electric current. One approach consists in representing microconstriction phenomena by surface contact parameters: The share coefficient and the thermal and electrical contact resistances, which depend on the contact temperature. The aim of this work is to determine the share coefficient and the contact temperature through a numerical model on a microscopic scale. This surface approach does not make it possible to correctly represent the temperature profiles, with the peak temperature, observed in the immediate vicinity of the interface and thus to define, in practice, the contact temperature correctly. That is why another approach is proposed with the introduction of a low thickness layer (third body) at the level of the interface the electric and thermal resistances of which are equivalent to the electrical and thermal contact resistance values. In this case, the parameters of the model are reduced to the thickness of the arbitrarily fixed layer and equivalent electric and thermal conductivities in the thin layer, the partition coefficient and the contact temperature becoming implicit. The two types of thermoelectric contact models are tested within the framework of the numerical simulation of a spot welding test. The nugget growth development is found to be much different with each model.

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