北京工人体育场开口单层扁薄拱壳罩棚钢结构整体稳定性能研究

Study on overall stability of steel canopy structure with open single-layer flat thin arch shell in Beijing Workers’ Stadium

北京工人体育场钢结构罩棚为周边设置摩擦摆支座的开口单层扁薄拱壳结构。为提升结构整体稳定性,采用考虑结构整体初始缺陷的4等分杆件模型进行有限元模拟,针对拱壳整体形态、构件截面规格和支座刚度共计3类11个参数进行单变量敏感性分析,评估结构在特征值屈曲分析、弹性和弹塑性全过程分析下的受力性能。分析表明:弹性全过程分析临界系数与特征值屈曲分析临界系数间具有强线性相关性,二者比值平均为0.535;结构塑性折减系数平均值为0.418;拱壳整体形态类参数的敏感性相对较高,其中拱端高差敏感性最高;构件截面规格类参数中,拱肋和外环梁截面规格的敏感性较高,支座刚度的敏感性相对较低。提出了结构整体稳定设计流程,结合特征值屈曲敏感性分析结果、构件承载力富余度和弹塑性全过程分析出铰杆件类型进行综合分析,有助于提高结构整体稳定设计效率。

The steel canopy structure of Beijing Workers’ Stadium is an open single-layer flat thin arch shell structure with friction pendulum isolation bearings around it. In order to improve the structural overall stability efficiently, finite element modelling was conducted considering overall initial imperfection of the structure and four segments subdivision of the components. Univariate sensitivity analysis was carried out including eleven parameters in three categories, e.g., the overall shape of the arch shell, the sectional size of the components and the support stiffness. The mechanical properties of the structure were evaluated through buckling analysis, elastic and elastoplastic whole process analysis. The results show that a strong linear correlation between the critical coefficient of elastic whole process analysis and buckling analysis is found. The average ratio of the former to the latter is 0.535. The average plastic reduction coefficient is 0.418. Parameters on overall shape of the arch shell are relatively sensitive, among which the height difference of the arch ends is the most sensitive one. The sensitivity of arch and outer ring beam is relatively high among the parameters of sectional size of components. The sensitivity of support stiffness is relatively low. The design process of structural overall stability was proposed. The overall stability design efficiency could be improved by synthetic analysis of sensitivity analysis result of eigenvalue buckling analysis, load bearing capacity redundancy of the component and the failure member type in elastoplastic whole process analysis.