单层平面索网玻璃幕墙结构作为一种新型结构形式,以建筑造型美观、构件轻巧纤细,广泛应用于大型公共建筑中,其具有柔性大、阻尼小等特点,且结构具有一定的几何非线性。在对其进行抗震设计时,基于线弹性假设的振型分解反应谱法可能具有一定的局限。为此,首先推导地震荷载作用下单层平面索网结构的非线性振动方程和非线性频率,其次通过计算该模型在四类场地最不利地震动作用下的结构非线性响应,得到单层索网幕墙结构的非线性反应谱,将其和线弹性单质点的反应谱进行比较,最后通过与地震模拟振动台试验结果的对比,证明结论的正确性。
Cable net facades as a new kind of glazing system are widely used with many advantages, such as pleasing aesthetics and easy constructability. With the characteristics of weak stiffness, light weight, small damping, cable net facade is obviously geometrically nonlinear, and the response spectrum method may have some limitations for the seismic design of cable net facades. The nonlinear vibration differential equation and vibration frequency of the cable net under earthquake was deduced, and a geometrically nonlinear single-degree of freedom model was obtained. With the geometrically nonlinear single-degree of freedom model, the nonlinear seismic response of the cable net was calculated with time history method under four types of site soils. The linear and nonlinear acceleration and displacement spectra were compared thoroughly. Shaking table tests were conducted to verify the accuracy of the nonlinear response spectrum.