| In this paper, firstly using the continuum technique for floor slabs, the differential equations of horizontal vibration for a tall building frame-shear wall-thin walled member cooperating system with stepped parameters, in which flexure and torsion are coupled, have been derived. The analytical solution of these equations is complicated by its coupling and stepped parameters. Secondly, using the ODE (Ordinary Differential Equation) Solver, which is a program developed for solving various ODE, the fore ten vibration frequencies and vibration modes have been obtained. |