【作者】 陆锋；

【导师】 孙炳楠； 楼文娟；

【作者基本信息】 浙江大学 ， 结构工程， 2001， 博士

【摘要】 随着科学技术的发展和施工工艺的进步，各种外形美观、结构新颖的大跨度柔性屋盖结构被广泛应用于体育馆、飞机库、剧场等公共建筑。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，因此深入研究大跨度柔性屋盖结构的风荷载及风振响应具有极其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，对大跨度平屋面结构的风振机理、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，设计制作了大跨度平屋面结构在四周封闭、四周敞开、有女儿墙、无女儿墙、墙体突然开孔各种不同情况下的刚性模型和气动弹性模型，解决了刚性模型同时测定上下表面风压而又不允许测压管影响周围风场的模型制作问题，建立并完善了考虑弗劳德数等一系列相似参数模拟的气动弹性模型的设计制作方法，获得了大跨度平屋面在各种情况下的屋面风压分布系数和风振响应规律，并进行了对比分析。 在理论分析方面，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度平屋面结构的风振响应分析。通过理论计算结果与气动弹性模型风洞试验结果的相互比较，指出采用时程分析法进行大跨度平屋面的风振响应分析所得结果是正确的，准定常假设在大跨度平屋面结构的风振响应分析中是不适用的，在准定常假设的基础上进行的模态分析所得风振响应规律和时程分析一致，但计算结果偏大许多。并由此从位移风振系数的角度提出了对基于准定常假设下的模态分析法的修正。最后通过对大跨度平屋面结构的风报系数的研究，提出了在实际工程设计中，采用位移风振系数来计算大跨度平屋面的等效静力风荷载既正确又方便使用，并且给出了大跨度平屋面结构在不同屋面刚度下的位移风振系数计算公式，以供设计参考。更多还原

【Abstract】 Along with the development of science and technology, a number of long-span flexible roof structures with beautiful shapes and new structural systems are widely applied into the public constructions, for example, gymnasium, hangar and theater. 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 at home and abroad. So it is important to study on wind load and wind-induced dynamic response for long-span flexible roof structures in the field of engineering and research.Based on wind tunnel test and theoretical analysis, the vibration mechanism, vibration shape, dynamic response and wind load factor of long-span flat roofs subjected to wind excitation are analyzed systematically in this dissertation, and some valuable results are obtained.In the matter of wind tunnel tests, the rigid and aeroelastic models for long-span flat roof structures in these cases, with or without parapets, closed or unclosed and opening a hole suddenly, are designed. The question that wind pressure upper surface and under surface of rigid models can be tested at the same time and the flexible vinyl tubes connected to pressure taps can’t influence the turbulence is solved commendably. The method to simulate the aeroelastic properties of prototype in consideration of a series of similarity coefficients including Froude number is established. Through the wind tunnel tests for rigid and aeroelastic models, the aerodynamic pressure coefficients and dynamic responses are obtained for these long-span flat roof structures. And a comparative analysis is also performed.In the matter of theoretical analysis, 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 flat roof structures are calculated infrequency domain and time domain separately. Based on the comparison of the computed results and experimental dates, some important conclusions can be obtained. The results obtained from the analysis method in time domain agree with experimental dates much better than the results obtained from the spectral analysis method. The quasi-static assumption can not be adopted in the analysis on wind-induced dynamic responses for long-span flat roof structures. The rules of dynamic responses obtained by the spectral analysis method are similar to those obtained by the analysis method in time domain, but the value is much larger. So the spectral analysis method based on the quasi-static assumption is modified in the present study. Finally, the wind load factor of long-span flat roof structures is discussed, and an important piece of advice is inferred from it. For engineering design, it is better to use wind load factor defined the ratio of wind-induced total displacement to static displacement for computing the equivalent static wind load of long-span flat roof structures. And the formula to calculate the wind load factor is provided when the stiffness of the roof varies.更多还原