网架结构竖向抗震性能评估的等效简化模型  

Simplified Equivalent Model for Vertical Seismic Performance Evaluation of Space Truss

作　　者：相阳[1] 毋凯冬 罗永峰[1] 沈祖炎[1] 

机构地区：[1]同济大学建筑工程系,上海200092

出　　处：《湖南大学学报（自然科学版）》2018年第1期44-51,共8页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51378379)~~

摘　　要：为建立分析效率高、计算精度高的网架结构竖向抗震性能评估方法,采用考虑结构质量分布的模态推覆分析荷载模式,对基于整体刚度参数的等效单自由度体系建立方法进行了改进.分析了网架结构竖向振动受重力作用影响显著、且竖向振动显著不对称的特点.假定网架结构向上振动时的等效荷载-变形关系为完全弹性,建立了简化的模态等效单自由度体系模型.给出了基于简化模型分析网架结构竖向地震反应和评估其竖向抗震性能的基本过程.数值算例表明,所提等效简化模型方法可较为精确地预测网架结构的竖向位移反应(跨中位移误差小于5%)和进入塑性的杆件分布位置,同时,简化方法计算耗时大幅低于非线性时程分析,易被设计工程师掌握使用.In order to establish an efficient and accurate procedure for the vertical seismic performance evaluation of space truss structures,a modal pushover load pattern, taking the structural mass distribution into consideration, was adopted so as to modify the establishing process of the equivalent single-degree-offreedom （ESDF） systems based on the overall structural stiffness parameter. The characteristic of the vertical vibration of space truss was investigated, which is influenced by gravity and obviously asymmetric. By assuming the equivalent load-deformation relationship of the ESDF system to be ＂one-side＂ elastic, the simplified modal ESDF systems for space truss structures were established. Basic processes for both vertical seismic response analysis and vertical seismic performance evaluation of space trusses were given. It is demonstrated by a numerical example that the proposed equivalent-simplified-model-based procedure can yield accurate vertical displacement response （error of central nodal displacement is less than 5%） and can approximately locate the inelastic members of space truss structures. Meanwhile, the time consuming of the proposed simplified procedure is much less than that of the nonlinear response history analysis. Moreover, for practical engineers, the proposed approach is pretty concise and easy to use.

关 键 词：平板网架 抗震性能 竖向地震反应 模态推覆分析 等效单自由度体系 

分 类 号：TU391[建筑科学—结构工程]