Temperature Effect of Composite Girders with Corrugated Steel Webs Considering Local Longitudinal Stiffness of Webs

The theoretical calculation formula for the temperature effect of composite box beams with corrugated steel webs and arbitrary temperature gradient distribution is derived based on the structural characteristics of such beams. This is achieved by considering the deformation coordination condition of the steel and concrete interface, as well as taking into account the longitudinal constraint effect of the web. An analysis is conducted to compare the results obtained from a fine finite element numerical example with those from the theoretical formula. This study also investigates the height of the common flexural zone of corrugated steel web and concrete, confirming the correctness of the theoretical formula. The findings indicate that, when 10% of the height of the corrugated steel web is considered as the common flexural area, there is optimal agreement between the theoretical values and finite element values, resulting in calculated results that are more consistent with actual stress states in this type of box girder bridge. Furthermore, it is observed that the interfacial shear force and interface slip between the steel and concrete in composite beams are not uniformly distributed along their longitudinal axis. Specifically, the interfacial shear force follows a hyperbolic cosine function along this axis, reaching its maximum value at mid-span while being zero at both ends. On the other hand, the interface slip follows a hyperbolic sine function along this axis, reaching its maximum value at the beam end while being zero within the span. It should be noted that factors such as the interface slip stiffness, temperature difference, and linear expansion coefficient have a significant influence on the temperature effects in composite beams. In addition to these factors, a reasonable arrangement of shear nails on steel plates has been identified as an effective method for mitigating adverse effects.