平行分离双幅桥气动导数识别的混合强迫振动试验法

发布时间：2018-10-25 11:05

【摘要】：自由振动试验法(FreeV法)用于平行分离双幅桥气动导数识别时,由于人工初始激励不同,节段模型产生的气动干扰不同,进而导致气动导数识别结果规律性差,识别数据离散性大。为此,提出了混合强迫振动试验法(MFV法),并对比分析了MFV法和FreeV法识别出的气动导数,以及基于MFV法和FreeV法的二维颤振分析结果与节段模型测试结果。研究结果表明:无论是上游桥还是下游桥,MFV法识别的气动导数均离散性较小,随折算风速的变化规律明确;而FreeV法识别的气动导数离散性较大,随折算风速的变化规律较差,尤其是受气动干扰效应影响较大的下游桥;基于MFV法预测的颤振临界风速与节段模型测试结果较为接近,而基于FreeV法预测的颤振临界风速与节段模型测试结果的偏差较大,尤其是下游桥,偏差更为显著;相比于FreeV法,MFV法能更为准确地模拟平行分离双幅桥的气动干扰效应,其颤振预测结果更准确。
[Abstract]:When the free vibration test method (FreeV) is used to identify the aerodynamic derivatives of parallel separation double-amplitude bridges, the aerodynamic interference produced by the segmental model is different due to the different initial artificial excitation, which leads to the poor regularity of the identification results of the aerodynamic derivatives. The recognition data is discrete. A hybrid forced vibration test method (MFV method) was proposed, and the aerodynamic derivatives identified by MFV method and FreeV method were compared and analyzed. The results of two-dimensional flutter analysis based on MFV method and FreeV method were compared with those of segmental model test. The results show that both upstream bridge and downstream bridge, the aerodynamic derivative identified by MFV method is less discrete, and the variation law of aerodynamic derivative with reduced wind speed is clear, while the variation law of aerodynamic derivative identified by FreeV method is worse than that of FreeV method. The critical flutter velocity predicted by MFV method is close to the test results of segmental model, while the critical flutter wind speed predicted by FreeV method deviates greatly from the measured results of segmental model. Compared with the FreeV method, the MFV method can simulate the aerodynamic interference effect of the parallel separated double-amplitude bridge more accurately, and the flutter prediction results are more accurate.
【作者单位】：汕头大学土木与环境工程系;同济大学桥梁结构抗风技术交通行业重点实验室;广东省高等学校结构与风洞重点实验室(汕头大学);同济大学土木工程防灾国家重点实验室;上海市城市建设设计研究总院;
【基金】：国家自然科学基金资助项目(51308330,91215302) 桥梁结构抗风技术交通行业重点实验开放基金项目(KLWRTBMC12-01)
【分类号】：U441.3

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