【作者】 王珩；

【导师】 孙炳楠；

【作者基本信息】 浙江大学 ， 结构工程， 2003， 硕士

【摘要】 随着科学技术的发展和施工工艺的进步，新建的体育场的看台往往覆盖着各种外形美观、结构新颖的大跨度柔性屋盖结构。风流经屋面时，会在屋面的大部分区域产生强大的吸力，并引起柔性屋面的风振。目前国内外对大跨度柔性屋盖结构的竖向风振研究很少，本文研究的体育场大跨网架屋盖结构的风荷载及风振响应作为大跨度柔性屋盖结构的一个专题，具有重要的工程应用价值和学术研究意义。 本文采用风洞模型试验和计算机数值计算相结合的方法，对台州体育中心看台屋盖的风振机理、风振形态、风振响应以及风振系数进行了系统研究，取得了一些有意义的结论。 在风洞试验方面，通过对台州体育中心屋盖刚性模型在模拟大气边界层风洞中进行的不同风向角下的风洞试验所得数据的研究，获得了结构在各种情况下的屋面风压分布规律，并且绘制了台州体育中心屋盖在各个风向角下的屋盖平均风压系数和脉动风压系数分布等值线图。 在理论分析方面，建立合理的有限元模型，利用刚性模型风洞试验获得的各种不同情况下屋面各节点的平均风压系数和脉动风压时程，在频域内和时域内进行了大跨网架屋盖结构的风振响应分析。在频域内，采用背景模态分析法，通过计算得到对结构振动能量贡献最大的一阶背景模态，从而得到结构脉动响应的均方根值；在时域内，采用直接积分法求出结构响应的时间历程，并且通过统计，同样得到结构脉动响应的均方根值。然后通过两种方法计算结果的相互比较，指出在准定常假设的基础上进行的背景模态分析法所得风振响应规律和时程分析法所得基本吻合，且可以考虑到高阶频率对振动的影响。最后通过对大跨网架屋盖结构的风振系数的研究，提出了在实际工程设计中，采用位移风振系数来计算大跨屋盖的等效静力风荷载既正确又方便使用，并且给出了台州体育中心看台屋盖进行分块统计后的位移风振系数，以供设计参考。更多还原

【Abstract】 Along with the development of science and technology,the stands of stadium are often covered with long-span flexible roof structures with beautiful shapes and new structural systems. When wind flows around roofs,the airflow will be separated to form a high suction zone,and the flexible roofs will suffer from wind-induced buffeting response. So far,a limited number of research papers are related to dynamic responses of long-span flexible roofs. Long-span grid roof is a special topic of long-span flexible roof structures,and it is important to study on wind load and wind-induced dynamic response in the field of engineering and research.Based on wind tunnel test and theoretical analysis,the vibration mechanism,vibration shape,dynamic response and equivalent wind load factor of the long-span grid roof of Taizhou Stadium subjected to wind excitation are analyzed systematically in this dissertation,and some valuable results are obtained.In the matter of wind tunnel tests,the distribution rules of roof under various wind directions are obtained through the data got from the wind tunnel tests for rigid model of long-span grid roof of Taizhou Stadium. Furthermore,the isoline maps of mean wind pressure coefficients and RMS wind pressure coefficients of the structure under various wind directions are plotted .In the matter of theoretical analysis,modeling with finite element method,using the local mean wind pressure coefficients and time history of fluctuating pressures determined in wind tunnel,the wind-induced dynamic responses for long-span grid roof structures are calculated in frequency domain and time domain separately. In frequency-domain,the background mode that has the most contribution to the buffeting energy of the structure is calculated using the background modal analysis method,thus the RMS of the dynamic responses of long-span grid roofs is obtained. On the other hand,the RMS of the dynamic responses is also obtained by direct integral method in time-domain. After the comparison of the results of two methods,several important conclusions can be made. The rules obtained from the background modal analysis method based on the quasi-steady assumption in frequency-domain aresimilar to those obtained by the analysis method in time-domain,and the influence of high modes can be considered. Finally,the dissertation suggests that for engineering design,it is better to use equivalent wind load factor defined the ratio of wind-induced total displacement to static displacement for computing the equivalent static wind load of long-span grid roof structures,And the equivalent wind load factor of the roof of Taizhou Stadium is calculated.更多还原