铁路混凝土箱梁的振动与噪声频谱特性研究

发布时间：2018-06-06 00:42

本文选题：混凝土箱梁 + 振动　；参考：《应用力学学报》2014年01期

【摘要】：为了研究混凝土箱梁的振动与噪声频谱特性,以成灌铁路跨度为32m的单线混凝土简支箱梁为研究对象,开展了现场试验研究、理论分析、有限元模拟。研究结果表明:箱梁顶、底板的弯曲振动是结构噪声产生的根源,其局部振动特性可由板壳或实体有限元分析得到;该箱梁的结构噪声在1/3倍频程、中心频率为63Hz处出现最大值,且具有明显的"有调性";车速在144~160km/h范围内变化时,箱梁总体噪声级变化较小,标准差在1dB以内;基于底板振动加速度近似推测结构噪声的方法具有可行性,预测值与实测值的偏差在5%以内;该箱梁在60~70Hz范围出现共振,并且该频率范围内声辐射效率接近最大值,二者共同导致了峰值噪声的产生。受板厚和材料的限制,声辐射效率的峰值频率变化较小,因此改变共振频率对降噪分析具有重要意义。
[Abstract]:In order to study the vibration and noise spectrum characteristics of concrete box girder, the field test, theoretical analysis and finite element simulation were carried out on the single line concrete simply supported box girder with span of 32 m. The results show that the bending vibration of the top and bottom plate of the box girder is the root of the structure noise, and the local vibration characteristics can be obtained by the finite element analysis of the plate, shell or solid, and the structural noise of the box girder is 1 / 3 times frequency range. The center frequency of the box girder is the maximum at 63Hz and has obvious "modulation", when the speed changes in the range of 144~160km/h, the overall noise level of box girder changes little, and the standard deviation is within 1dB. The method of estimating the structure noise based on the vibration acceleration of the bottom plate is feasible, the deviation between the predicted value and the measured value is less than 5%, the box girder has resonance in the 60~70Hz range, and the acoustic radiation efficiency is close to the maximum in the frequency range. Both of them lead to the production of peak noise. Due to the limitation of plate thickness and material, the peak frequency of acoustic radiation efficiency varies little, so it is very important to change the resonance frequency for noise reduction analysis.
【作者单位】：西南交通大学土木工程学院;
【基金】：国家自然科学基金(51308469;51378429) 新世纪优秀人才支持计划(NCET-10-0701) 863计划(2011AA11A103) 高等学校博士点基金(20110184110020) 西南交通大学扬华之星项目
【分类号】：TB533;U448.213

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