Refinement and Verification of the Structural Stress Method for Fatigue Life Prediction of Resistance Spot Welds Under Variable Amplitude Loads 2000-01-2727
The work presented here builds on the practical and effective spot weld fatigue life prediction method, the structural stress method (SSM), that was developed at Stanford University. Constant amplitude loading tests for various spot weld joint configurations have been conducted and the SSM has been shown to accurately predict fatigue life.
In this paper refinements to the structural stress approach are first presented, including a variable amplitude fatigue life prediction method based on the SSM and Palmgren-Miner's rule. A test matrix was designed to study the fatigue behavior of spot welds under tensile shear loading conditions. Constant amplitude tests under different R-ratios were performed first to obtain the necessary material properties. Variable amplitude tests were then performed for specimens containing single and multiple welds. Experimental and finite element data are then compared in order to illustrate the ability of the SSM to include load ratio effects and predict life for variable amplitude loading. Finally, test data and life predictions based on the SSM for specimens of mixed material and mixed thickness are presented.
Citation: Sheppard, S., Pan, N., Bai, Z., and Sheu, Y., "Refinement and Verification of the Structural Stress Method for Fatigue Life Prediction of Resistance Spot Welds Under Variable Amplitude Loads," SAE Technical Paper 2000-01-2727, 2000, https://doi.org/10.4271/2000-01-2727. Download Citation
Sheri Sheppard, Ning Pan, Zhengxian Bai, Yih-Chyun Sheu
Stanford Univ., General Motors Corp.
International Body Engineering Conference & Exposition