Estimation of fatigue life of welded joint using vibration-fatigue computational model
Date
2015
Authors
Subramanian, Eniyavan
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Abstract
Heavy vehicle structures are made from welded carbon steel frames. During operation these frames are subjected to random dynamic loads, which induce fatigue at the welded joints. A Finite Element based process for calculating fatigue life of welded joint under single excitation random loading is proposed in this study. The proposed method com-bines Equivalent Equilibrium Structural Stress (E2S2) method for weld fatigue and PSD based vibration fatigue technique for handling random loads. Fatigue life of a welded T-joint is analysed using the proposed method in frequency domain and validated against a transient dynamic analysis. The main advantage of the proposed method is the analysis run time is reduced almost 12 times compared to transient analysis.
Effect of geometric changes on weld fatigue life is studied. It is found the tube thickness increase at lower thickness ranges significantly increases the fatigue life compared to higher thickness ranges.
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Keywords
FEA, Weld fatigue, Vibration fatigue, PSD