Fatigue strength evaluation of welded structural details in corrugated steel web girders

Fatigue strength evaluation of welded structural details is of practical significance in the design of corrugated steel web girders in highway bridges and industrial structures. In this paper, the fatigue strengths of corrugated steel web girders with several welded structural details and welding methods are analytically examined by fatigue tests of corrugated web beams and small-size welded joints. The stress concentration & distribution characteristics of corrugated web beams were analysed using finite element analysis. The beam test results showed that the structure with scallops or notches in the flange has lower fatigue strength and that with butt joints is prone to suffer from shear crack on the corrugated web. Within the inside range of the scallop, the stress concentration becomes greater with the increase of scallop radius and the tension flange contributes significantly to the bending capacity of corrugated steel web beams. The tests for small-size welded joints indicated their applicability in the analysis and prediction of S-N relationship of the test corrugated steel web beams. Finally, the fatigue crack propagation lives of weld joints were compared with those of test corrugated steel web beams with respect to related design Categories of the AASHTO LRFD Bridge Design Specifications.