Study on Shear Lag Effect in Tapered Girders with Corrugated Steel Webs Considering Positive and Negative Resal Effects

In tapered girders with corrugated steel webs (CSWs), the Resal effect significantly alters the effective shear force transmitted through the CSWs, thereby changing the shear force distribution across the section and affecting the shear lag effect. This study presents a pioneering analysis of the interaction between the Resal effect and shear lag effect, aiming to develop an analytical framework that accurately captures the shear lag effect. The Resal effect can be classified into positive and negative types, each causing distinct shear force redistribution patterns that result in varying impacts on the shear lag effect. To address these variations, a modified method is developed based on the principle of minimum potential energy, incorporating both positive and negative Resal effects. This approach enhances the accuracy of shear lag predictions in tapered girders with CSWs. The validity of the proposed method is confirmed through experimental data and finite-element (FE) simulations. In contrast, conventional methods derived from prismatic girders yield substantial errors and fail to accurately predict the shear lag effect in tapered cases, underscoring the essential role of the Resal effect in such analyses. Furthermore, a detailed decomposition analysis reveals the underlying mechanisms by which the Resal effect influences shear lag behavior. Specifically, a positive Resal effect leads to increased normal stress and higher shear lag coefficients—indicative of a positive shear lag effect. Meanwhile, a negative Resal effect induces a negative shear lag effect, resulting in reductions in both values. These findings highlight the necessity of incorporating the Resal effect into shear lag analysis for tapered girders with CSWs, as it is critical for achieving accurate predictions and ensuring structural reliability.