基于概率性人行荷载模型的楼板结构振动分析

发布时间：2018-04-29 16:17

本文选题：楼板振动 + 舒适性　；参考：《工程力学》2014年02期

【摘要】：为评估实际楼板结构在可能承受的人行荷载作用下的振动性能,运用动力测试和数值模拟相结合的方法对某实际楼板结构进行了动力特性及人行激励下的概率性响应分析。首先利用基于频响函数的冲击动力测试,识别了楼板结构实际的模态参数。然后考虑各行人个体产生激励的差异性及随机的人行路径等因素,构建了不同随机步态参数组合的单人及人群多分量荷载模型;基于动力测试所得的模态特性,分别计算了在所构建的概率性荷载作用下的多模态响应;对得到的大量响应样本统计分析得到了单人及人群行走荷载下的响应分布以及某一振动水平发生的概率;结果表明人致振动响应服从近似的正态分布,行人随机性的步态参数中步频对响应的分布起控制作用,此外得到的响应分布特性可对实际楼板结构的人致振动进行概率性的评估。在人群荷载响应计算时,对测得的人活动加速度响应进行自由衰减响应分析得到不同加速度水平时结构基本模态特性的变化,结果表明频率随振动加速度幅值的变化相对较小,而阻尼的变化相对较明显。该文研究可为类似工程的人致振动概率性评估提供参考。
[Abstract]:In order to evaluate the vibration behavior of the actual floor structure under the action of the possible pedestrian load, the dynamic characteristics and the probabilistic response of a practical floor structure under pedestrian excitation are analyzed by using the method of dynamic test and numerical simulation. Firstly, the actual modal parameters of floor structure are identified by the impact dynamic test based on frequency response function (FRF). Then considering the difference of individual excitation and random walking path, the single and crowd multi-component load models with different random gait parameter combinations are constructed, which are based on the modal characteristics of dynamic test. The multimodal response under the constructed probabilistic load is calculated, and the response distribution under the walking load and the probability of a certain vibration level are obtained by statistical analysis of a large number of response samples. The results show that the response of human induced vibration is controlled by the approximate normal distribution, and the gait frequency plays a controlling role in the random gait parameters of pedestrians. In addition, the response distribution characteristics obtained can be used to evaluate the probability of human induced vibration of the actual floor structure. When the load response of the crowd is calculated, the free attenuation response of the measured acceleration response is analyzed to obtain the change of the basic modal characteristics of the structure with different acceleration levels. The results show that the frequency varies relatively little with the amplitude of the vibration acceleration. The change of damping is relatively obvious. This study can be used as a reference for the probabilistic evaluation of human induced vibration in similar projects.
【作者单位】：兰州理工大学甘肃省土木工程防灾减灾重点实验室;兰州理工大学防震减灾研究所;
【基金】：甘肃省科技攻关项目(2GS057-A52-008)
【分类号】：TU311.3

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