Empirical Modelling of a Prototype Resistance Spot Welding Machine

C. G. Ozoegwu, C. N. Oti, I. P. Okokpujie, E. T. Akinlabi

Research output: Contribution to journalConference articlepeer-review

Abstract

Resistance spot welding (RSW) has been extensively used in the automotive and aerospace industries over the years. The weld quality of spot welds is affected by the welding parameters like electrode force, weld time, electrode current and workpiece size/shape parameters like workpiece thickness. This study focuses on the effect of electrode force, weld time and workpiece thickness on the weld quality of mild steel samples where the aim is to correlate the weld strength to welding parameters of a portable RSW machine installed at the Nigerian Liquefied Natural Gas (NLNG) laboratory of the Department of Mechanical Engineering, University of Nigeria, Nsukka. Lap shear weld samples are tested for strength, and the results are used to develop an empirical model. The developed model has a coefficient of determination of 0.6365 and a correlation coefficient of 0.7978. Hypothesis testing at 5% significance level discovered that the most significant predictor is the cross interaction of the workpiece thickness and electrode force with p-value of 0.02367 and that the model is significant with a p-value = 0.0453. The model is validated by further welding operations and tensile shear tests which gave a percentage error not exceeding 12.92% but was as low as 6.35%.

Original languageEnglish
Article number032101
JournalJournal of Physics: Conference Series
Volume1378
Issue number3
DOIs
Publication statusPublished - 18 Dec 2019
Externally publishedYes
Event3rd International Conference on Engineering for Sustainable World, ICESW 2019 - Ota, Nigeria
Duration: 3 Jul 20198 Jul 2019

Keywords

  • central composite design
  • resistance spot welding
  • statistical regression
  • tensile shear test
  • weld nugget
  • weld strength

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