Influence of P–Δ Effects on Inter-Story Drift and Modal Characteristics of Frame–Tube Tall Buildings

AbstractThis study investigates the influence of P–Δ (secondary) effects on inter-story drift and modal characteristics of frame–tube tall buildings. Using nonlinear static and dynamic analyses on representative frame–tube models, we quantify variations in modal frequencies, mode shapes, and lateral displacements with and without inclusion of P–Δ effects. Results demonstrate that P–Δ effects significantly amplify inter-story drifts and alter modal parameters, especially in taller configurations. Recommendations for design implications and practical modelling strategies are provided.