周期点阵夹芯板减振隔声性能的实验研究与数值分析

发布时间：2018-05-12 03:04

本文选题：周期点阵夹芯板 + 禁带　；参考：《北京交通大学》2017年硕士论文

【摘要】：周期点阵夹芯板不仅具有轻质高强、节能保温等多种优良特性,同时具有频率禁带特性,即处于频率禁带范围内的振动或波动无法在结构中传播,从而实现减振隔声的目的。本文分别对单层N型和X型两种新型周期点阵夹芯板的减振性能、多层金字塔型周期点阵夹芯板的隔声性能进行了实验研究与数值分析。通过振动传输实验测得N型和X型点阵夹芯板的幅频响应曲线,并与数值计算结果进行了对比分析,分别考虑了拾取点位置、支撑形式和位置、激励点位置及夹芯板泡沫填充等影响因素。通过隔声实验测得金字塔型点阵夹芯板的传声损失曲线,并与有限元数值计算结果进行了对比分析。得出以下结论:(1)N型和X型点阵夹芯板对于禁带频率范围内的振动具有良好的隔振性能,实验得到的衰减域频率范围与数值结果基本吻合。夹芯板的芯体结构形式对隔振性能影响较大,实验与数值模拟结果均显示N型点阵夹芯板具有超宽禁带,衰减域宽度可达到400Hz,隔振性能优于X型点阵夹芯板。N型和X型周期点阵夹芯板良好的隔振效果使得点阵夹芯板在减振隔振领域具有广阔的前景(2)N型和X型点阵夹芯板的禁带特性主要源于其内部芯体的周期性点阵排布方式。实验与数值模拟结果均显示随着周期数增加,夹芯板的隔振性能更优。不同的支撑形式和位置、激励点位置等因素对夹芯板隔振性能影响很小。泡沫填充能够有效增大结构的衰减频率范围及衰减程度,特别是对于高频振动具有良好的减弱效果,对周期点阵夹芯板的隔振性能起到了积极作用。(3)实验与数值模拟结果均显示金字塔型点阵夹芯板对于特定频率范围内的声波具有很好的隔声性能,传声损失可达35dB,衰减域宽度可达到450Hz。金字塔型周期点阵夹芯板的良好隔声效果有利于其在隔声降噪领域的应用。(4)声波在通过点阵夹芯板时由于层间空气与结构的耦合作用会导致传声损失曲线的衰减域频率范围与振动禁带频率范围存在偏差。点阵夹芯板的材料密度越小,耦合作用越强,偏差越大。且材料密度很小时,传声损失普遍减小,声波无明显的衰减域。
[Abstract]:The periodic lattice sandwich panel not only has many excellent characteristics, such as light and high strength, energy saving and heat preservation, but also has the characteristics of frequency band gap, that is, the vibration or wave within the range of frequency forbidden band can not be propagated in the structure, so as to achieve the purpose of reducing vibration and isolating sound. In this paper, the vibration absorption performance of two new periodic lattice sandwich panels, single layer N type and X type, and the sound insulation performance of multi-layer pyramid periodic lattice sandwich panels are studied experimentally and numerically. The amplitude-frequency response curves of N-type and X-type lattice sandwich panels were measured by vibration transmission experiments, and the results were compared with those of numerical calculation. The position, support form and position of pick-up points were considered, respectively. The influence factors such as the position of the excitation point and the foam filling of the sandwich panel. The acoustic loss curves of pyramid lattice sandwich panels were measured by sound insulation experiments and compared with the results of finite element numerical calculation. The following conclusions are drawn: the N type and X type lattice sandwich panels have good isolation performance for vibration in the band gap frequency range, and the frequency range in the attenuation domain obtained by the experiment is in good agreement with the numerical results. The core structure of sandwich panel has great influence on the vibration isolation performance. The experimental and numerical simulation results show that the N-type lattice sandwich panel has an ultra-wide band gap. The attenuation domain width can reach 400 Hz, and the vibration isolation performance is better than that of X type lattice sandwich plate. N type and X type periodic lattice sandwich board. The band gap of the core is mainly due to the periodic lattice arrangement of the inner core. Both experimental and numerical results show that the vibration isolation performance of sandwich panels is better with the increase of the number of cycles. The vibration isolation performance of sandwich panel is influenced little by different supporting form and position, excitation point position and so on. Foam filling can effectively increase the attenuation frequency range and attenuation degree of the structure, especially for high frequency vibration. The results of experiment and numerical simulation show that the pyramid lattice sandwich panel has good sound insulation performance for the specific frequency range. The loss of sound transmission can reach 35 dB, and the width of attenuation domain can reach 450 Hz. The good sound insulation effect of pyramid periodic lattice sandwich panel is advantageous to its application in the field of sound insulation and noise reduction.) the sound wave passing through the lattice sandwich panel will lead to the attenuation of the sound transmission loss curve due to the coupling between the air and the structure between the layers. There is a deviation between the domain frequency range and the vibration band gap frequency range. The smaller the material density, the stronger the coupling and the greater the deviation. When the material density is very small, the sound transmission loss is generally reduced, and the sound wave has no obvious attenuation region.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB535.1

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