Analytical Method for Shear Stress in CSW Composite Girders Accounting for Cross-Beam Constraint Effects near Intermediate Supports

The shear behavior of corrugated steel web (CSW) composite girders near intermediate supports differs fundamentally from that of conventional beam segments due to the rigid restraint of concrete cross-beams, yet current design codes incorrectly assume the CSWs resist the entire shear force. This paper presents a refined analytical method, based on a three-beam composite model, that explicitly accounts for the cross-beam constraint effect. By assuming a quadratic parabolic distribution of the additional shear-flow intensity along the constraint zone, a closed-form expression for the effective shear force carried by the CSWs is derived. The proposed method is validated against three-dimensional finite element (FE) simulations and existing experimental data, and further corroborated by a parametric study covering varying structural configurations. The results confirm a shear redistribution mechanism characterized by “CSWs unloading and flange sharing.” At the section nearest to the cross-beam, the CSWs actually carry only 65.41% of the total shear force, while the flanges share approximately 35%. In contrast, the conventional code method, which neglects flange shear contribution, severely overestimates CSWs’ shear stress, producing an error as high as 35.29% at the section adjacent to the cross-beam. These findings demonstrate that the cross-beam constraint must be considered in shear design, especially near supports, and the proposed method offers a rational and accurate alternative to existing code provisions.