超高层建筑多自由度气弹模型的优势及制作方法

发布时间：2018-03-09 13:28

本文选题：高层建筑　切入点：横风向涡致振动　出处：《振动与冲击》2014年17期 　论文类型：期刊论文

【摘要】：首先简要对比了测力天平、刚性模型测压、强迫振动、气动弹性模型等四种试验手段的特点,然后着重分析了底部弹性支撑的摆式气弹模型和多自由度气弹模型试验结果的差异,分析发现,对超高超柔的方截面建筑而言,摆式模型所得的横风向风致响应在小风速下比多自由度模型略大,而在包含横风向共振风速在内的大风速下则明显大于多自由度模型,其气动阻尼特性、气动刚度特性和表面风压相干性等倾向于使摆式模型出现相对较大的风致响应。究其原因,是因为只模拟一阶模态的摆式模型在反映流固互制气弹效应方面不够真实且不及多自由度模型精细,即参振模态的不同(包括参振模态数量、高阶与低阶平动频率比、扭转与平动频率比)会使振动形式发生改变,进而影响振动时的气弹效应并改变振动位移。在此结论的基础上,提出了多自由度气弹模型改进设计方法,该方法考虑了低阶与高阶频率比、平动与扭转频率比的可调性,同时解决了模型弯剪振型成分的可控制性和阻尼调节等问题,以期为实际项目的多自由度模型制作和相关研究提供便利和参考。
[Abstract]:Firstly, the characteristics of four test methods, such as force balance, rigid model, forced vibration and Aeroelastic model, are briefly compared. Then, the difference between the test results of the pendulum Aeroelastic model and the multi-degree-of-freedom Aeroelastic model is analyzed, and it is found that, for the ultra-flexible square section building, The wind-induced response of the pendulum model is slightly larger than that of the multi-degree-of-freedom model under the small wind speed, while the aerodynamic damping characteristic is obviously greater at the large wind speed including the cross-wind resonance wind speed than the multi-degree-of-freedom model. Aerodynamic stiffness characteristics and surface wind pressure coherence tend to cause relatively large wind-induced response of the pendulum model. It is because the pendulum model which only simulates the first-order mode is not true enough to reflect the gas-elastic effect of fluid-solid interaction and is less precise than the multi-degree-of-freedom model, that is, the different parametric modes (including the number of parametric modes, the ratio of high-order and low-order translational frequencies). The ratio of torsion to translational frequency will change the vibration form, thus affect the Aeroelastic effect and change the vibration displacement. On the basis of the conclusion, an improved design method for the multi-degree-of-freedom Aeroelastic model is proposed. The method takes into account the tunability of the frequency ratio of lower order to higher order, the ratio of translational and torsional frequencies, and solves the problems of the controllability and damping regulation of the modal bending and shear mode components. The purpose of this paper is to provide convenience and reference for the establishment of multi-degree of freedom model and related research.
【作者单位】：武汉大学土木建筑工程学院;
【基金】：国家自然科学基金资助项目(51178359)
【分类号】：TU973.213

【参考文献】