点支式幕墙鱼腹式索桁架支承体系动力特性

Dynamic characteristics of fish-shaped cable truss support system in point-supported curtain wall

考虑温度变化及几何非线性影响,采用连续化理论导出了点支式玻璃幕墙预应力鱼腹式索桁架支承体系非线性振动方程。通过Galerkin方法,将偏微分程转化为常微分方程,并采用L-P法及KBM法对常微分方程进行了求解。结合工程实例讨论分析了温度变化、振幅、外激励等因素对点支式玻璃幕墙预应力鱼腹式索桁架支承体系非线性振动的影响。算例表明,点支式玻璃幕墙预应力鱼腹式索桁架支承体系固有频率随着温度的升高而减小,其非线性振动呈现"硬弹簧"特性。

Taking the temperature effect and geometric nonlinearity into consideration,the nonlinear vibration equation of prestressed fish-shaped cable truss support system in point-supported glass curtain wall was derived by assuming the support system as a continuum membrane.By the Galerkin method,the partial differential equation was transformed into ordinary differential equation which was then solved with L-P(Lindstedt-Ponicaré) method and KBM(Krylov-Bogoliulov-Mitropolsky) method.The effects of temperature,vibration amplitude,and exterior excitation on the nonlinear vibration were discussed with an engineering example.The result indicates that the natural frequency of the support system will decrease,with the increase of temperature,and the vibration shows hard spring characteristics.