Subsystem‐Based Analytical Expressions for the Dynamic and Stability Analysis of Uniform One‐Bay Coupled Shear Walls Using the Three‐Field CTB Beam

Two additional deformation mechanisms—local shear and axial extensibility of the walls—have recently been incorporated into the analysis of coupled shear walls to overcome the lack of accuracy of classical continuous models. Although several generalized continuous models and solution techniques have been proposed, they usually entail high computational costs and require advanced user expertise. In this paper, a three‐field CTB beam—constructed from the parallel coupling of an extensible Timoshenko beam and a shear beam—is employed to derive, for the first time, simple and directly applicable analytical expressions for estimating the fundamental frequency and the global critical buckling load of uniform one‐bay coupled shear walls, both symmetric and asymmetric. Using a subsystem‐based approach, the static lateral displacement is decomposed into three independent subsystems: a bending–shear beam, a bending beam, and a shear beam. Approximate eigenvalue expressions are derived for each subsystem with sufficient accuracy, enabling direct evaluation of their natural frequencies and critical loads. These eigenvalues are then combined through Dunkerley's principle to obtain conservative global estimates of the generalized three‐field CTB beam response. To improve predictive accuracy, correction factors are introduced for both dynamic and stability analyses, keeping the estimates within acceptable engineering tolerances. A thorough parametric study encompassing a wide range of structural behaviors confirms the suitability of the proposed analytical solutions for practical applications. Maximum deviations remain within ±3.87% for the dynamic case and ±5.33% for the buckling case, providing a reliable and low‐complexity alternative for preliminary structural design.