ABSTRACT
Steel-concrete composite bridges are widely used because of their good structural properties but suffer from fatigue problems due to increasing vehicle loads and speeds. In order to investigate the fatigue response at welded gusset plates of steel-concrete composite bridges, finite element models of long-span steel-concrete composite bridges with three loading conditions and different gusset plate thickness are established, and the stress time history analysis is carried out. Finite element results show that the under the most unfavorable condition among the three conditions, the maximum stress occurs when the fatigue vehicle passes through the critical point. When the gusset plate thickness is 20 mm, the stress peaks for TC1, TC2 and TC3 conditions are 23.3 MPa, 27.4MPa and 14.8 MPa, respectively. Stress peak values decrease with an increase in thickness. Stress peaks for 12 mm, 16 mm and 20 mm thicknesses are 47.1 MPa, 37.3 MPa and 27.4 MPa, respectively.
