Analysis of Deflection Behavior in Tapered Cantilever Composite Girders with Corrugated Steel Webs

Owing to the reduced shear stiffness of corrugated steel webs (CSWs), shear deflection must be accounted for in estimating the total deflection of box girders with CSWs (BGCSWs). Most existing investigations into the deflection behaviour of such girders are based on prismatic girder models, in which the CSWs are presumed to resist the entire external shear force – thus contributing to shear deflection – while the concrete flanges provide only flexural rigidity, leading to bending deflection. In contrast, in tapered BGCSWs, bending moment induces a redistribution of shear stresses within the cross-section, resulting in a deflection mechanism that fundamentally deviates from predictions by conventional methods. Furthermore, unlike prismatic girders, the moment of inertia in tapered girders varies continuously along the span, significantly increasing the complexity of bending deflection computation. To extend classical beam theory to the analysis of tapered BGCSWs, this paper introduces the concept of an equivalent effective moment of inertia derived via Simpson’s integration. A general methodology is proposed to determine this equivalent inertia for arbitrarily tapered cross-sections. By incorporating the influence of shear deflection, a comprehensive analytical framework is established for predicting the deflection of tapered BGCSWs. The accuracy of the proposed theoretical method is validated through experimental tests and finite element (FE) simulations.