不同激励模式下桥梁实测阻尼比差异

发布时间：2018-01-30 03:37

本文关键词： 桥梁工程阻尼比激励模式半功率带宽法自由衰减法　出处：《振动与冲击》2016年03期 　论文类型：期刊论文

【摘要】：收集和分析了国内外学者对结构物阻尼比的实测结果,指出了当前桥梁阻尼比研究成果的局限性。为了弥补当前桥梁阻尼比实测结果匮乏的局限,针对三座典型桥梁进行了阻尼比测试,分析了影响桥梁阻尼比的主要因素。该研究发现:桥梁的阻尼比不是定值,它与桥梁的类型、测试时的激励方式、阻尼比的处理方法、测试环境等有较大的相关性。激励强度越大,测试的阻尼比数值越大。车辆激励作用下的阻尼比数值明显大于环境激励下的阻尼比数值。相同激励模式下,不同的阻尼比处理方法所计算的阻尼比数值差距较大。半功率带宽法计算的阻尼比数值的离散性要大于利用自由衰减法计算的阻尼比。建议桥梁结构阻尼比的测试中需要保证激励的一致性,避免在采样过程中出现激励程度差距较大的激励模式。
[Abstract]:This paper collects and analyzes the measured results of the damping ratio of structures at home and abroad, and points out the limitations of the current research results on the damping ratio of bridges, in order to make up for the lack of the measured results of the current bridge damping ratios. The damping ratio of three typical bridges is tested and the main factors influencing the damping ratio are analyzed. It is found that the damping ratio of the bridge is not a fixed value, the type of the bridge and the type of the bridge, and the excitation mode of the test. The damping ratio of the treatment method, testing environment and so on has a greater correlation. The greater the intensity of excitation. The larger the damping ratio is, the bigger the damping ratio is under the excitation of the vehicle, which is obviously higher than the value of the damping ratio under the environmental excitation. The difference of damping ratio calculated by different damping ratio processing methods is large. The dispersion of damping ratio calculated by half-power bandwidth method is greater than that calculated by free attenuation method. It is suggested that the damping ratio of bridge structure should be measured. It is necessary to ensure the consistency of motivation in the test. Avoid the incentive mode in the sampling process where the incentive degree gap is large.
【作者单位】：交通运输部公路科学研究院;
【分类号】：U446
【正文快照】： 阻尼作为在桥梁结构动力响应计算中一个重要因素,其取值的大小直接影响着动力响应的计算结果,但是其机理、模型、取值等方面的研究仍然落后与其他研究,严重制约着结构动力学的发展[1]。Leger等[2]利用8种不同的阻尼模型对结构进行了地震时程分析,不同模型计算的延性系数、耗散

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