Coupled lateral-torsion vibration of asymmetric shear-wall structures

This paper presents an analysis of dynamic performance of asymmetric shear-wall structures. In the analysis, the asymmetric shear-wall structure is replaced by an equivalent thin-walled beam with lateral flexure and warping torsion deformations. Due to the asymmetry of the floor plan, the natural vibration of the structure is a coupled vibration, where lateral flexure vibrations in two orthogonal principal directions couple with a warping torsion vibration. Based on the continuum technique and the DʹAlembertʹs principle, the governing differential equation of natural vibration and the corresponding eigenvalue problem for asymmetric multi-bent wall structures are derived. By employing the Galerkin technique, a method of solution is proposed for analysis of coupled vibration of generally asymmetric shear-wall structures and for estimate of the coupled natural frequencies and associated mode shape in coupled vibration. Results obtained from the proposed method for the example structure show good agreement with those of finite element analysis. It has been shown that the proposed analysis provides an efficient and accurate means of dynamic analysis of asymmetric shear-wall structures in coupled vibration.