A New Characterization Approach of Weld Nugget Growth by Real-Time Input Electrical Impedance


The in-process changes of weld nugget growth during the Resistance Spot Welding were investigated based on the resistance of input electrical impedance. To compute the time varying resistance of input electrical impedance, the welding voltage and current signals are measured simultaneously and then converted into complex-valued signals by using Hilbert transform. Comparing with the dynamic contact resistance as reported in literature, it showed that the time varying resistance of input electrical impedance can be accurately correlated with the physical changes of weld nugget growth. Therefore, it can be used to characterize the in-process changes of weld nugget growth. Several new findings were reported based on the investigation of spot welds under no weld, with and without weld expulsion conditions.

Share and Cite:

Wong, Y. and Pang, X. (2014) A New Characterization Approach of Weld Nugget Growth by Real-Time Input Electrical Impedance. Engineering, 6, 516-525. doi: 10.4236/eng.2014.69054.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Scharff, R. and Caruso, D. (1990) Complete Automotive Welding Metals and Plastics. Albany, New York.
[2] Harlin, N., Jones, T.B. and Parker, J.D. (2003) Weld Growth Mechanism of Resistance Spot Welds in Zinc Coated Steel. Journal of Material Processing Technology, 143-144, 448-453.
[3] Dickinson, D.W., Franklin, J.E. and Stanya, A. (1980) Characterization of Spot Welding Behavior by Dynamic Electrical Parameter Monitoring. Welding Journal, 59, 170-176.
[4] Gedeon, S.A., Sorensen, C.D., Ulrich, K.T. and Eagar, T.W. (1987) Measurement of Dynamic Electrical and Mechanical Properties of Resistance Spot Welds. Welding Journal, 66, 378-385.
[5] Cho, Y. and Rhee, S. (2002) Primary Circuit Dynamic Resistance Monitoring and Its Application to Quality Estimation during Resistance Spot Welding. Welding Journal, 81, 104-111.
[6] Wang, S.C. and Wei, P.S. (2001) Modeling Dynamic Electrical Resistance during Resistance Spot Welding. Transactions of the ASME, Journal of Heat Transfer, 123, 576-585.
[7] Garza, F. and Das, M. (2001) On Real Time Monitoring and Control of Resistance Spot Welds Using Dynamic Resistance Signatures. Proceeding of the 44th IEEE-Midwest Symposium on Circuits and Systems, Dayton, 14-17 August 2001, 41-44.
[8] Tan, W., Zhou, Y., Kerr, W. and Lawson, S. (2004) A Study of Dynamic Resistance during Small Scale Resistance Spot Welding of Thin Ni Sheets. Journal of Physics D: Applied Physics, 37, 1998-2008.
[9] Ling, S.-F., Luan, J., Li, X.C. and Ang, W.L.Y. (2006) Input Electrical Impedance as Signature for Nondestructive Evaluation of Weld Quality during Ultrasonic Welding of Plastics. NDT & E International, 39, 13-18.
[10] Ling, S.-F., Zhang, D., Yi, S. and Foo, S.W. (2006) Real-Time Quality Evaluation of Wire Bonding Using Input Impedance. IEEE Transactions on Electronics Packaging Manufacturing, 29, 280-284.
[11] Fu, L.Y., Ling, S.-F. and Tseng, C.-H. (2007) On-Line Breakage Monitoring of Small Drills with Input Impedance of Driving Motor. Mechanical Systems and Signal Processing, 21, 457-465.
[12] Ling, S.-F., Wan, L.-X., Wong, Y.-R. and Li, D.-N. (2010) Input Electrical Impedance as Quality Monitoring Signature for Resistance Spot Welding. NDT & E International, 43, 200-205.
[13] Julius, S.B. and Allan, P.G. (2000) Random Data: Analysis and Measurement Procedures. 3rd Edition, Wiley, New York, 518-543.
[14] Boctor, S.A. and David, A.B. (1992) Electrical Circuit Principles. Prentice Hall Inc., Englewood Cliffs, 489-536.
[15] Cho, Y. and Rhee, S. (2000) New Technology for Measuring Dynamic Resistance and Estimating Strength in Resistance Spot Welding. Measurement Science & Technology, 11, 1173-1178.
[16] Chen, J.Z. and Farson, D.F. (2006) Analytical Modeling of Heat Conduction for Small Scale Resistance Spot Welding Process. Journal of Material Processing Technology, 178, 251-258.
[17] BS 1140:1993 (1993) Specification for Resistance Spot Welding of Uncoated and Coated Low Carbon Steel. BSI Publications, London.

Copyright © 2022 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.