FATIGUE STRENGTH OF WELDED JOINTS IN STEEL-CONCRETE COMPOSITE SLAB USING L-SHAPED SHEAR CONNECTORS

Abstract

 In this study, the fatigue strength of welded joints in steel-concrete composite slabs was investigated by fatigue testing. In addition, the local stress around the welded joint was evaluated through finite element analysis. In the test, fatigue cracks occurred at the toes of boxing welds of L-shaped shear connectors as a result of stress concentration due to the local out-of-plane bending deformation of the steel plates around the boxing weld. This local deformation can be produced by the steel and concrete behaving independent of one another locally near welds when the bond at their interface is lost. The test results demonstrated that the fatigue assessment of welded joints in a composite slab can be performed using the hot-spot stress approach. Then, actual composite slabs with different structural characteristics were analyzed to investigate the local stress behavior around welded joints, and their fatigue performance was assessed based on the hot-spot stress approach.