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1.
高伟夫  马蕙 《应用声学》2021,40(5):698-704
为提升其隔声性能,通过有限元法数值分析,比较了不同位置墙板的连接方式对房间隔声性能的影响。结果表明:(1)侧墙墙板柔性连接处理对侧向传声的抑制作用显著,当侧墙墙板采用柔性连接后,房间的隔声量在低频段平均可以提升3 dB左右;(2)公共隔墙墙板的柔性连接对房间低频段隔声量提升不明显,甚至在160 Hz、400 Hz、500 Hz等频率下隔声量有所降低。最后,基于模拟分析结果对装配式墙体连接方式提出了改进策略。  相似文献   

2.
In additional to the screw connection affecting the sound transmission characteristics of the panel-stud partition,the spacing of screws is also considered as a factor in predicting the sound insulation of the partition.It can be modeled either as a series of independent point connections,or as a line connection depending on the screw spacing.For small screw spacing,the connection between panel and stud can be treated as a line connection,from which a higher sound transmission effect can be achieved.Whilst for a larger screw spacing,it can be treated as an independent point connection,from which a lesser sound transmission through the partition can be achieved accordingly.The distinction between these two kinds of connection is also related to the frequency.Usually,half bending wavelength of a panel will be treated as a distinct frequency.Experimental results of double leaf partition with diverse screw spacing significantly demonstrated their influences on sound reduction.Some prediction methods for partitions with different screw spacing are also reviewed in this paper.It should be noted that the impact of screw spacing effecting on the sound insulation of partitions of wood stud and light-weight metal stud is different.  相似文献   

3.
This study deals with the feedforward active control of sound transmission through a simply supported rectangular panel using vibration actuators. The control effect largely depends on the excitation method, including the number and locations of actuators. In order to obtain a large control effect at low frequencies over a wide frequency, an active transmission control method based on single structural mode actuation is proposed. Then, with the goal of examining the feasibility of the proposed method, the (1, 3) mode is selected as the target mode and a modal actuation method in combination with six point force actuators is considered. Assuming that a single input single output feedforward control is used, sound transmission in the case minimizing the transmitted sound power is calculated for some actuation methods. Simulation results showed that the (1, 3) modal actuation is globally effective at reducing the sound transmission by more than 10?dB in the low-frequency range for both normal and oblique incidences. Finally, experimental results also showed that a large reduction could be achieved in the low-frequency range, which proves the validity and feasibility of the proposed method.  相似文献   

4.
Precast panels are widely used for the construction of large industrial buildings, trade centres and apartment houses. These buildings have to comply with prescribed noise and thermal requirements, so the possibility to accurately estimate the sound reduction index of such panels is of vital importance. The sound reduction index can be determined through measurements carried out in a laboratory or on an already mounted real-scale panel, but both solutions present problems. For example, precast structures consisting of two concrete panels coupled via an interlayer can be very bulky and heavy, and measurements in standard sound transmission laboratories may be impossible to carry out. In some countries, predictions based on theoretical models are accepted in lieu of measurements. Following this approach, the application of simple models, not accounting for the influence of coincidence and of losses, is not sufficient to make acceptable predictions. In this paper, an alternative method to estimate the sound reduction index of precast panels is proposed. Different panels have been considered in the study, each of which has been modelled by a mathematical representation found in the literature. It will be shown that all of these models can be synthesised by a common mathematical formulation, allowing the sound reduction index to be determined from point mobility measurements. The effectiveness of the new method has been investigated by comparing predicted and measured results, obtained in a sound transmission laboratory satisfying existing ISO standards.  相似文献   

5.
Multi-layer structures have issues with sound insulation at low and mid-frequencies due to mass-air-mass resonance. The purpose of this study is to investigate improvements to the sound insulation performance of multi-layer structures using a microperforated panel (MPP), which can absorb well over a wide frequency range. Although MPPs have been investigated over the last several decades, almost all studies have been conducted in terms of sound absorption. Herein the sound transmission loss of multi-layer structures with flexible MPPs of infinite extent is theoretically investigated. The calculation is based on the wave equation and the equation of panel vibration including the effect of perforation of the panel. Additionally to consider a more realistic sound insulation performance, the effect of the directional distribution of the incident energy in a reverberation chamber is taken into account. Experiments are conducted using an acoustic tube to validate the calculated results and the reverberation chamber method to verify the actual sound insulation characteristics. Both experiments agree well with the theoretically calculated perforation effects. Consequently, MMPs are confirmed to improve the deterioration of sound insulation performance due to mass-air-mass resonance of multi-layer structures.  相似文献   

6.
The control of sound transmission through panels is an important noise control problem in the aerospace, aeronautical, and automotive industries. The trend towards using lightweight composite materials that have lower sound insulation performance is a negative factor regarding low frequency transmission loss. Double-panel partitions with the gap filled with sound absorption materials are often employed to improve the sound insulation performance with reduced added weight penalty. However, in the low frequency range, the strong coupling between the panels through the air cavity and mechanical paths may greatly reduce the sound transmission performance, making it even lower than the performance of a single panel in some frequency ranges. In this work, an experimental investigation of a new kind of hybrid (active/passive) acoustic actuator is presented. The idea consists of replacing the acoustic absorption material by a hybrid actuator aiming at improving the transmission loss at low frequencies without altering the passive attenuation. A prototype of the system is tested in a plane wave acoustic tube setup. Different kinds of SISO feedforward control implementations were used to attenuate the sound power transmitted through the hybrid active–passive panel using an error microphone or a particle velocity sensor placed downstream with respect to the sample panel. Measurement results of the transmission loss with active and hybrid attenuation are presented and discussed.  相似文献   

7.
提出了一种计算上下面板非对称的三明治夹芯板隔声性能的方法。通过对非对称夹芯梁表观抗弯曲刚度的计算,得到对应夹芯板随频率变化的表观抗弯刚度,代入4阶的控制方程,应用模态展开法可以方便地计算简支非对称夹芯板的隔声量。对4种定制的3层非对称碳纤维夹芯板进行了理论计算和实验测试对比,在频率范围100~3150 Hz内,计权隔声量误差在3 dB以内。着重分析了面板对称性、芯层剪切模量对隔声性能的影响,发现在夹芯板面密度一定时,芯层剪切模量对夹芯板的隔声性能影响最为显著。当芯层剪切模量较小时,上下面板非对称分布导致吻合频率显著降低,对夹芯板的整体隔声亦不利。   相似文献   

8.
The sound transmission between adjacent rooms has been modeled using a finite-element method. Predicted sound-level difference gave good agreement with experimental data using a full-scale and a quarter-scale model. Results show that the sound insulation characteristics of a party wall at low frequencies strongly depend on the modal characteristics of the sound field of both rooms and of the partition. The effect of three edge conditions of the separating wall on the sound-level difference at low frequencies was examined: simply supported, clamped, and a combination of clamped and simply supported. It is demonstrated that a clamped partition provides greater sound-level difference at low frequencies than a simply supported. It also is confirmed that the sound-pressure level difference is lower in equal room than in unequal room configurations.  相似文献   

9.
To avoid the undesirable effects of a faulty sealing of outlet boxes, it is common to insert a gypsum board layer in the middle of a double frame partition. In this paper, measured sound reduction index data for double frame partitions, with and without a gypsum board layer insert, are presented. The results obtained show that the sound insulation decreases at low frequencies due to the presence of the internal layer. The weighted sound reduction index, which is strongly affected by the low frequency sound insulation, decreases by 7-8 dB. Since these degradations are greater than those resulting from small gaps in partitions, it can be concluded that the insertion of a gypsum board layer in the middle of a double frame partition is not a suitable solution to the undesirable effects of faulty sealing of outlet boxes.  相似文献   

10.
For the interior sound field formed by the complex vibrating structure,an identification approach of panel acoustic contribution based on equivalent source method(ESM)was presented.The normal velocity on the surface of vibrating structure was first reconstructed by using interior nearfield acoustic holography based on ESM and the prediction of whole interior enclosed sound field was realized.Then the sound pressure produced by each panel at the interested field point was respectively replaced by the radiated pressure of the enclosed interior sound field which is formed by the equivalent virtual sources located near the surface of the cavity.Combining with the reconstructed normal surface velocity,the acoustic contribution of each panel to any position in the cavity was obtained by transforming the complex enclosed non-free field into the simple interior free field.Numerical simulations and experiments are conducted,and the influences of the number of the equivalent sources and the distance between them and the reconstructed surface have been investigated.The results show that the proposed method is easier to be implemented with the same accuracy than the traditional analysis method.  相似文献   

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