大跨弦支穹顶结构的振动模态与地震响应分析

Vibration Model and Seismic Response for the Long-Span Suspend-Dome Structure

针对常州市体育中心体育馆屋盖采用的大跨椭球型弦支穹顶结构,利用大型有限元软件ANSYS建立了三维空间有限元模型。基于子空间迭代法求解了结构的振动模态,采用考虑结构静力初始状态的非线性动力分析方法,分析了结构的地震响应。研究结果表明:大跨椭球形弦支穹顶结构的自振频率比较密集,一阶振型为结构沿短轴方向的反对称振动;结构在地震激励下的位移、应力和索力变化均较小;有杆件初始弯曲时结构的最大响应增加,最大误差不超过5%;从整体上看,大跨椭球形弦支穹顶结构具有较高的整体刚度和良好的抗震性能。

Pointing to the long-span ellipse suspend-dome structure adopted in Changzhou Sport Center,the finite element software ANSYS is adopted to construct the three-dimensional finite element analysis model.Based on the subspace iteration method,the vibration model of the structure is solved.Then,the nonlinear dynamic analysis method considering the initial static state is adopted to analyze the structural seismic response.Results show that the self-vibration frequencies are highly concentrated,and the first vibration model is asymmetric style in the short axis direction;the displacement,stress and cable forces under earthquake excitation is relatively small;when the member initial curvature exists,the maximum structural response increases,but the maximum error does not exceed 5%.Generally,the long-span ellipse suspend-dome structure has high integral stiffness and good seismic performance.