强迫振动法提取桥梁气动导数研究

利用节段模型的自由振动法来提取气动导数，这种方法其装置简单、易于实现，但在试验中结果并不完美。原因之一是模型可能会受到涡的影响，并且在高风速时，信号受干扰严重，信噪比较低。另外激振方式的不同也会造成重复性差。强迫振动法一直被认为是提取气动导数最精确的方法，但由于装置较为复杂，研究和实施此法者目前较少。笔者给出了针对两种桥梁断面进行的一次强迫振动法实验检验，表明效果好。

Identification of aerodynamic derivatives for bridge sections by forced oscillation method

It has become common practice to obtain unsteady aerodynamics forces of the bridge deck section by free oscillation method in the wind engineering. As this method is easy to be used and yields satisfying results for many cases, but through our past experience we found that the test results using this method sometimes were unreliable because of the influence of vortex-induced vibration and some other reasons. In this paper, a forced oscillation method is introduced which was used at China Aerodynamics Research and Development Center to identify all aerodynamic derivatives of an airplane. The test results indicate that this method can obtain all aerodynamic derivatives accurately and conveniently.