0
TECHNICAL PAPERS

Ultimate Strength and Failure Mechanism of Resistance Spot Weld Subjected to Tensile, Shear, or Combined Tensile/Shear Loads

[+] Author and Article Information
Yuh J. Chao

Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208e-mail: chao@sc.edu

J. Eng. Mater. Technol 125(2), 125-132 (Apr 04, 2003) (8 pages) doi:10.1115/1.1555648 History: Received February 05, 2002; Revised August 12, 2002; Online April 04, 2003
Copyright © 2003 by ASME
Your Session has timed out. Please sign back in to continue.

References

Ewing, K. W., Cheresh, M., Thompson, R., and Kukuchek, P., 1982, “Static and Impact Strengths of Spot-Welded HSLA and Low Carbon Steel Joints,” SAE Paper 820281.
VandenBossche, D. J., 1977, “Ultimate Strength and Failure Mode of Spot Welds in High Strength Steels,” SAE paper 770214.
Radaj,  D., 1989, “Stress Singularity, Notch Stress and Structural Stress at Spot-Welded Joints,” Eng. Fract. Mech., 34(2), pp. 495–506.
Radaj,  D., and Zhang,  S., 1993, “On the Relations Between Notch Stress and Crack Stress Intensity in Plane Shear and Mixed Mode Loading,” Eng. Fract. Mech., 44(5), pp. 691–704.
Zhang,  S., 2001, “Approximate Stress Formulas for a Multiaxial Spot Weld Specimen,” Weld. J. (Miami), 80(8) 201s–203s.
Zhang,  S., 1999, “Approximate Stress Intensity Factors and Notch Stresses for Common Spot-Welded Specimens,” Weld. J. (Miami), 78(5), pp. 1735–1795.
Zhang,  S., 1999, “Stress Intensities Derived from Stresses Around a Spot Weld,” Int. J. Fract., 99, pp. 239–257.
Zhang,  S., 1997, “Stress Intensities at Spot Welds,” Int. J. Fract., 88, pp. 167–185.
Wung,  P., 2001, “A Force-Based Failure Criterion for Spot Weld Design,” Exp. Mech., 41(4), pp. 107–113.
Wung,  P., Walsh,  T., Ourchane,  A., Stewart,  W., and Jie,  M., 2001, “Failure of Spot Welds Under In-Plane Static Loading,” Exp. Mech., 41(1), pp. 100–106.
Zuniga, S., and Sheppard, S. D., 1997, “Resistance Spot Weld Failure Loads and Modes in Overload Conditions,” Fatigue and Fracture Mechanics: 27th Volume, ASTM STP 1296, R. S. Piascik, J. C. Newman, and N. E. Dowling, eds., American Society for Testing and Materials, pp. 469–489.
Barkey,  M. E., and Kang,  H., 1999, “Testing of Spot Welded Coupons in Combined Tension and Shear,” Exp. Tech., 23(5), pp. 20–22.
Lee,  Y., Wehner,  T., Lu,  M., Morrissett,  T., Pakalnins,  E., 1998, “Ultimate Strength of Resistance Spot Welds Subjected to Combined Tension and Shear,” J. Test. Eval., 26(3), pp. 213–219.
Lin,  S. H., Pan,  J., Wu,  S., Tyan,  T., and Wung,  P., 2002, “Failure Loads of Spot Welds under Combined Opening and Shear Static Loading Conditions,” Int. J. Solids Struct., 39, pp. 19–39.
Chao, Y. J., 2002, “Failure of Spot Weld: A Competition Between Crack Mechanics and Plastic Collapse,” Recent Advances in Experimental Mechanics—In Honor of Isaac M. Daniel, Kluwer Academic Publishers, pp. 245–256.
Dowling, N. E., Mechanical Behavior of Materials, Prentice Hall, New Jersey.
Zhang,  Z. L., Hauge,  M., Degard,  J., and Thaulow,  C., 1999, “Determining Material True Stress-Strain Curve from Tensile Specimens With Rectangular Cross-Section,” Int. J. Solids Struct., 36, pp. 3497–3516.
ANSI/AWS/SAE/D8.9-97, 1997, Recommended Practices for Test Methods for Evaluating the Resistance Spot Welding Behavior of Automotive Sheet Steel Materials, American Welding Society, Miami.
Zhou,  M., Hu,  S. J., and Zhang,  H., 1999, “Critical Specimen Sizes for Tensile-Shear Testing of Steel Sheets,” Weld. J. (Miami), 78(9), pp. 305s–312s.
Materials and Applications, 1998, Part II, Welding Handbook, 4 , 8th edition, American Welding Society.
AWS D8.7-88, SAE J-1188, 1987, Recommended Practices for Automotive Weld Quality—Resistance Spot Welding, American Welding Society.
Radaj, D., and Zhang, S., 1996, “Anschauliche Grundlagen fur Krafte und Spannungen in Punktgeschweisten Uberlappverbindungen, Konstruktion,” 48 , pp. 65–71.
Radaj, D., and Zhang, S., 1996, “Strukturspannungen am starren Kern in endlich berandeter Platte,” Konstruktion, 48 , pp. 195–199.
Sawhill, J. M., Jr., and Furr, S. T., “Spot Weldability Tests for High-Strength Steels,” SAE paper 810352.

Figures

Grahic Jump Location
Engineering and true stress-strain curves for the HSLA steel tested
Grahic Jump Location
Cross tension and lap-shear test sample geometries
Grahic Jump Location
Schematics showing the load-displacement curves of lap-shear and cross tension samples
Grahic Jump Location
Ultimate strength of the spot welds; batch A,B,C-USC data Batch D, Zuniga and Sheppard 11; batch E, Sawhill and Furr 24 (some data are shifted horizontally for clarity)
Grahic Jump Location
Global deformation and failure process of a lap-shear spot-weld sample: (a) initial configuration, (b) nugget rotation (align first with the loading line); (c) stretching, thinning, and necking, and (d) tensile fracture due to localized necking.
Grahic Jump Location
Fracture initiation site of a lap-shear spot-weld sample. The hairline at the bottom of the nugget is the crack.
Grahic Jump Location
Optical micrographs showing the stages of failure process of a lap-shear sample: (a), (b), and (c) show the progress of the localized necking and (d) final fracture (reproduced from Zuniga and Sheppard 11)
Grahic Jump Location
SEM fractograph (1000X) of a lap-shear sample: the circular dimple rupture microstructure indicating tensile fracture
Grahic Jump Location
Global deformation pattern (b) and the weld nugget pullout failure (c) of a cross tension sample
Grahic Jump Location
Optical micrograph of the cross section of a failed 1.5 mm specimen showing the pullout failure of the weld nugget around the nugget circumference (reproduced from Lin, et al. 14)
Grahic Jump Location
SEM fractograph (1000X) of a cross tension sample: the “fish scale” rupture microstructure indicating shear fracture
Grahic Jump Location
Assumed stress distribution around the weld nugget in a lap-shear sample
Grahic Jump Location
Assumed stress distribution around the weld nugget in a cross tension sample
Grahic Jump Location
Failure loads normalized with respect to batch A, lap-shear sample (ALS)
Grahic Jump Location
Failure strength of lap-shear and cross tension samples made of cold rolled steels with various ultimate tensile strength 24 and prediction by (7) (The predicted is shifted to the left (Mises) and right (Tresca) for clarity)
Grahic Jump Location
Tensile/shear mixed mode test sample geometry 13
Grahic Jump Location
Tensile/shear mixed mode test data 13 and prediction by (10) Normalized load=failure load/(nugget diameter x sheet thickness)

Tables

Errata

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In