Shear lag effect quantification and capacity modification of vertical corrugated steel plate composite shear walls with flange

This study elucidates the failure mechanism and proposes a capacity modification approach for vertical corrugated steel plate composite shear walls with flange (T-shaped and L -shaped), explicitly accounting for the shear lag effect. Through experimental measurements and refined finite element simulations, the evolution of strain and stress distributions at the bottom of the wall limbs is systematically investigated. The results reveal that the L -shaped specimen exhibits a considerably more pronounced shear lag effect than its T-shaped counterpart, attributable to sectional asymmetry and weaker restraint; conversely, the shear lag on the web limb of the T-shaped specimen is negligible when loaded along the flange direction. Utilizing the effective flange width method, parametric studies are conducted to evaluate the sensitivity of the shear lag coefficient to variables including shear wall height, corrugated steel plate angle and thickness, distributed rebar configuration, material strengths, and design axial compression ratio. Based on these parametric results, statistically recommended effective width coefficients with a 90% confidence interval are proposed, differentiated for long-limb and short limb flanges in compression and tension. Finally, the proposed coefficients are integrated into the existing shear capacity equations. The modified calculations demonstrate substantially improved accuracy and excellent agreement with experimental data, significantly outperforming unmodified code methods. This modification establishes a quantitative threshold for capacity error due to shear lag and provides a rational basis for the design of composite shear walls with unconventional cross-sections under seismic loading.