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Evaluation of Force-Based Spot Weld Modeling in Quasi-Static Finite Element Analysis
Technical Paper
2012-01-0537
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Evaluating spot weld separation is one of the most challenging tasks in a quasi-static simulation. There are several factors that exist in modeling welds analytically that can influence correlation to physical test. This paper presents 4 specific factors: spot weld representation, weld thickness, weld strength, and metal forming effects around spot welds.
There are many ways in which a spot weld can be modeled within an FEA model from mesh independent beams to mesh dependent hex clusters. While each modeling technique comes with its unique sets of advantages and disadvantages, a method is chosen to best balance correlation, model setup timing and computation time.
Dependent on the way the thickness of the spot weld is represented, artificial moments can be induced which misrepresents structural behavior.
The assigned yield strength of the spot weld influences the behavior of the joint. Simply assigning the yield strength to the parent metal yield strength can underestimate weld forces of the joint.
Metal forming effects are inherent to formed components that alter the virgin metal. Typical factors include strength gains or losses due to work hardening, thinning, thickening and residual stress. Therefore, if a spot weld is located on an area of severe thinning, it will lose joining strength.
This paper describes how to overcome the 4 types of limitations through alternative spot weld modeling techniques and discusses correction factors for quasi-static analysis load cases using DYNA-3D[1]. A Roof Strength evaluation is used to verify these parameters.
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Citation
Lee, H., Police, P., and Cory, C., "Evaluation of Force-Based Spot Weld Modeling in Quasi-Static Finite Element Analysis," SAE Technical Paper 2012-01-0537, 2012, https://doi.org/10.4271/2012-01-0537.Also In
References
- Livermore Software Technology Corporation, 7374 Las Positas Road, Livermore, CA “LS-DYNA_971 Keyword User's Manual page 8.123” May 2007
- Lee, H. Police, P. “Application of Failure Plastic Strain to Quasi-Static Finite Element Analysis for Projection Weld and Strain-based Spot Weld Evaluation,” SAE Technical Paper 2011-01-1074 2011 10.4271/2011-01-1074
- Yoda, S. Kumagai, K. Yoshikawa, M. Tsuji, M. “Development of a Method to Predict the Rupture of Spot Welds in Vehicle Crash Analysis,” SAE Technical Paper 2006-01-0533 2006 10.4271/2006-01-0533
- Malcolm, Skye Nutwell, Emily “Spot Weld Failure Prediction using Solid Element Assemblies” 6 th European LS-DYNA Users' Conference Gothenburg, Sweden 2007
- Wu, J. “Beam-type versus Solid-type Spot Weld in LS-DYNA,” SAE Technical Paper 2009-01-0354 2009 10.4271/2009-01-0354
- Ewing, K. Cheresh, M. Thompson, R. Kukuchek, P. “Static and Impact Strengths of Spot-Welded HSLA and Low Carbon Steel Joints,” SAE Technical Paper 820281 1982 10.4271/820281
- Tong, Wei Tao, Hong Jiang, Xiquan Zhang, Nian Marya, Manuel P. Hector, Louis G. Gayden, Xiaohong Q. “Deformation and Fracture of Miniature Tensile Bars with Resistance-Spot-Weld Microstructures” Metallurgical and Materials Transactions A 36A October 2005
- Lee, Hwawon “Development of Material Property to Compensate Sheet Metal Forming Influence for Quasi-Static Analysis” GM Internal Conference September 10 2007