Shear Tension Fatigue Behavior of Bonded Joint,Weldbonded Joint and Spot-welded Joint

Abstract:

A test was made on the fatigue life of structural bonded joints,weldbonded joints and spot-welded joints under different levels of stresses.Based on the hypothesis that load-life curve in single logarithm coordinate should be exponential curve,load-life curves of three kinds of joints were fitted by using of fatigue test data.Thus,fatigue performance of three kinds of joints was able to be described by these curves.And,a comparative analysis was made of the fatigure behavior of bonded joints,weldbonded joints.The study show that distribution of these fatigure test data follows a certain law.The fitted result proves that the hypothesis that load-life curve in single logarithm should be exponential curve is right.Fatigue strength of bonded joints is the highest of the three kinds of joints.On the contrary,fatigue strength of spot-welded is the lowest.Fatigue rupture behavior of weldbonded joint is more dangerous than that of bonded joint.Fatigue life of body joints can be improved by bonded process.These conclusions provide references for application of structural adhesive to vehicles.