An Enhanced Modular Frame-Shear Wall with Stiffening Frame: Thin-Walled Plate Critical Buckling Stress Calculation and Restraint Concrete Design

Experimental results of the modular frame-shear wall demonstrate that the unrestrained frame-shear wall structure is prone to out-of-plane buckling deformation at the steel plate edges, leading to tearing failure. For the concrete restraint frame-shear wall, the restraint components provide effective out-of-plane constraint, thereby enhancing the energy dissipation capacity. However, the constraint effect on the steel plate edges is still insufficient. Based on the test results, an enhanced modular frame-shear wall with stiffening frame is proposed. This structure demonstrates a more gradual stiffness degradation trend combined with favorable ductility and energy dissipation capacity. Through the buckling analysis of the substructure (corrugated steel plate and stiffening frame), it is revealed that the existence of an optimal design stiffness ratio exists between components. Furthermore, the recommended ranges of stiffening frame thickness, subplate width, and corrugation height are proposed. Moreover, the stiffness ratio between the corrugated steel plate and the stiffening frame should be, in accordance, within 0.95 ≤ ζ ≤ 5.5 . Finally, the calculation formula of substructure critical buckling stress and a design method for restraint concrete are established, which can be used for the design and application of such structures.