住宅建筑中相邻房间的侧向传声预测

侧向传声作为建筑中声传递的组成部分,对住宅的整体隔声效果具有重要的影响,通过将建筑中相邻房间的各建筑构件划分为若干子系统,应用统计能量分析(Statistical Energy Analysis,SEA)理论,从系统的声功率平衡的角度建立侧向传声的预测模型,在描述各路径的传声规律的同时确定主要传声路径。研究结果表明:当外围护结构为重质结构,且为匀质单一材料构造时,(1)在低频处,全程通过两相邻房间的侧墙或楼板的非通过隔墙的侧向路径成为主要侧向传声路径;(2)在中高频,各侧向路径的声压级差趋于一致,此时的建筑隔声性能取决于通过隔墙的直接路径上的声传递;(3)采用重质隔墙可以缩小侧向传声影响的频率范围。本研究为改善住宅的声环境质量及建筑隔声设计提供了理论依据。      

The prediction of airborne sound transmission between two rooms using first-order flanking paths

Airborne sound transmission between adjacent rooms can be predicted using the Standard EN 12354-1 (ISO 15712-1), which is equivalent to a first-order approximation of statistical energy analysis (SEA). This paper analyses airborne sound transmission between adjacent rooms in a masonry building, by comparing results obtained from EN 12354-1 to SEA predictions and measurements. It is shown that the restriction of the Standard to first-order flanking paths can lead to large errors in predictions when compared to measurements and SEA results taking into account all transmission paths. This is observed both for individual flanking paths and overall transmission between rooms, for which the Standard provides results similar to those obtained by the first-order approximation of SEA. The paper also looks at possible reasons why previous studies using the approach in EN 12354 have generally shown good agreement with measurements.     

Application of a finite-element model to low-frequency sound insulation in dwellings

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.     

住宅隔声的预测:计及侧向传声的简易方法

本文提出了一种预测房间隔声的方法，它考虑了侧向传声，而以容易得到有关于房屋布局，隔墙及其支撑的资料作为基础，分离了三种传声路长并作出解释，最后给出一些测量与计算之间相比较的例子。     

钢结构装配式住宅墙板连接方式对隔声性能的影响*

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。     

A chart for estimating the distance attenuation of flanking sound passing through open windows in the exterior wall of adjoining rooms and its experimental verification

Sound transmission between adjoining rooms is often influenced by a flanking sound passing through open windows placed in the exterior wall of the two rooms. It is important to predict such flanking sound propagation when considering the sound insulation between the adjoining rooms. In this paper, a chart for estimating the distance attenuation of the flanking sound, which is obtained from analysis using the boundary integral equation method, is first provided. Next, 1:10 scale model experiments are carried out. The experimental results are in good agreement with the chart, the effectiveness of the chart thus being verified.     

Flanking transmission of metal stud walls with different junction details

Measurements of the normalised flanking sound level difference of different gypsum board flanking walls are reported. Results of a “standard” wall construction confirmed some results of the current draft standard of DIN 4109. Different constructions with various junction details and different wall constructions are described and measurement results are presented. By additional measurements on the walls, a prediction model for the weighted flanking level difference is suggested, based on the methodology of EN 12354. For the flanking transmission prediction of path Ff, three transmission paths are proposed. The model gives good agreement between calculated and measured weighted flanking level difference except for the case where the transmission along the inner lining of the flanking wall is dominant. In this case the prediction underestimates measurements by up to 7 dB.     

The prediction of sound transmission through buildings using statistical energy analysis

Measurements were carried out on a building to evaluate the uses of statistical energy analysis for determining sound transmission performance. Coupling loss factors were measured and compared with predicted values. It was found that, in general, good agreement was obtained. The coupling loss factors were also used to calculate the sound pressure level, or surface velocity, of each subsystem in the building for a number of different sources. Comparison with the measured results gave an average error of 4 dB. Some large errors were obtained but these were due mainly to the omission of airborne flanking paths from the SEA model or due to the breakdown of the theory for specific coupling loss factors.     

Establishing a new acoustical laboratory, planning, experiments, experiences

A significant part of the input data for planning the acoustical quality of building is the result of laboratory measurements. Detailed modelling of complex phenomena of sound transmission, like structure borne sound propagation can be solved based on on well planned laboratory experiences. However it seems the constructional details of the testing facilities have important effect on the measured results. The paper describes the process of planning the testing facilities of the Laboratory of Building Acoustics, TU Budapest, which operate as a standardised laboratory, a modelling “tool” for flanking transmission in research and development and which is utilised in teaching too. Some results and conclusions of recent experiments are also reported and discussed here related to the sound reduction index of a heavy brick wall without and with flanking transmission, to the impact sound insulation between the rest of a stair and an adjacent room and also to a possibility to determine the reduction of impact sound transmission of floor coverings.     

A hybrid finite element – statistical energy analysis approach to robust sound transmission modeling

When considering the sound transmission through a wall in between two rooms, in an important part of the audio frequency range, the local response of the rooms is highly sensitive to uncertainty in spatial variations in geometry, material properties and boundary conditions, which have a wave scattering effect, while the local response of the wall is rather insensitive to such uncertainty. For this mid-frequency range, a computationally efficient modeling strategy is adopted that accounts for this uncertainty. The partitioning wall is modeled deterministically, e.g. with finite elements. The rooms are modeled in a very efficient, nonparametric stochastic way, as in statistical energy analysis. All components are coupled by means of a rigorous power balance. This hybrid strategy is extended so that the mean and variance of the sound transmission loss can be computed as well as the transition frequency that loosely marks the boundary between low- and high-frequency behavior of a vibro-acoustic component. The method is first validated in a simulation study, and then applied for predicting the airborne sound insulation of a series of partition walls of increasing complexity: a thin plastic plate, a wall consisting of gypsum blocks, a thicker masonry wall and a double glazing. It is found that the uncertainty caused by random scattering is important except at very high frequencies, where the modal overlap of the rooms is very high. The results are compared with laboratory measurements, and both are found to agree within the prediction uncertainty in the considered frequency range.     

Mechanisms of active control of noise transmission through triple-panel system using single control force on the middle plate

This paper presents an active triple-panel sound insulation structure with an idealized controllable point force acting on the middle plate. A novel analytical approach based on sound energy transmission rule is proposed to achieve the physical mechanism study. The transfer impedance matrix of the incident and middle plate is calculated using numerical approach. And the rule of sound energy transmission through the triple-panel structure is concluded by indirectly analyzing the radiated sound power of the three plates. Finally the physical mechanism of noise insulation is investigated from the point of view of the change in behaviors of energy transmission in controlled and uncontrolled conditions. Results obtained demonstrate that there exist four different energy transmission paths for four panel mode groups. The energy transmission is independent in each path and they are all of band-pass characteristic. The role of the middle plate and two cavities is very similar to the band-pass filter whose pass-band is different for different mode groups. The essence of active noise insulation lies in the fact that the energy transmission in each path is suppressed in its pass-band after control. This greatly improves sound insulation capability of the triple-panel structure and leads to sound propagation being blocked.     

利用混合FE-SEA方法的前围隔声性能优化设计*

为了提升某重型商用车前围的隔声性能,建立了用于分析前围传递损失的有限元-统计能量分析(FE-SEA)模型。针对前围结构复杂的特点,依据FE-SEA模型建模原则,提出了通过在表面创建声腔来确保能量在模型中的正确传递路径。将仿真结果与测试值对比,二者误差小于1.6 dB(A),验证了FE-SEA方法的准确性。用吸声材料与隔声材料复合设计前围声学包,采用正交试验法对前围声学包进行优化设计并对各个试验方案进行仿真计算。对仿真结果进行极差分析与方差分析,选出了在传递损失、重量和厚度三方面达到最佳平衡的声学包:毛毡(10 mm)+EPDM隔声垫(2 mm)。结果表明,优化后的前围传递损失在测试频率315 Hz～2000 Hz范围内最小提升了3.8 dB(A),最大提升了7 dB(A),前围的隔声性能得到较大的提升。     

Energy transmission in a mechanically-linked double-wall structure coupled to an acoustic enclosure

The energy transmission in a mechanically linked double-wall structure into an acoustic enclosure is studied in this paper. Based on a fully coupled vibro-acoustic formulation, focus is put on investigating the effect of the air gap and mechanical links between the two panels on the energy transmission and noise insulation properties of such structures. An approximate formula reflecting the gap effect on the lower-order coupled frequencies of the system is proposed. A criterion, based on the ratio between the aerostatic stiffness of the gap cavity and the stiffness of the link, is proposed to predict the dominant transmitting path, with a view to provide guidelines for the design of appropriate control strategies. Numerical results reveal the existence of three distinct zones, within which energy transmission takes place following different mechanisms and transmitting paths. Corresponding effects on noise insulation properties of the double-wall structure are also investigated.     

实验室隔声测量中试件洞填隙墙传声影响的检验

文章探讨了实验室建筑构件隔声测量中填隙墙传声影响的检验与修正方法。通过实验分析,给出了三种可用于不同隔声量构件的门、窗和玻璃试件隔声测量的填隙墙构造方式。     

三层平板结构声能流计算及传输规律

为了理解多层有源隔声结构的物理机理,同时优化被动隔声结构,需深入分析三层结构中声能量的传输规律。首先对三层板腔结构建模并求解系统的振动响应,然后用数值方法求解平板向封闭空间辐射声的声传输阻抗,并计算各层结构的辐射声功率。最后,通过分析各子系统所占的能量及各层结构四类模态组辐射声功率的变化获得声能量的传输规律。结果表明,按模态类型的不同,能量传输可等效认为存在四个传输通道,各通道的能量传输具有相似的带通特性,其成因在于不同的平板与空腔模态对的耦合强弱不同。      

嵌入式质量块对隔声门低频段隔声性能的影响

针对隔声门低频隔声性能差的问题，将嵌入式质量应用于隔声门中以提高隔声门在低频段的隔声性能，通过建立两个相邻混响室的有限元模型计算隔声门的隔声量。基于该模型，并结合隔声门低频隔声性能的评价方法，对在低频段影响隔声门有效隔声量的相关参数进行了参数关联性研究和优化，优化结果表明：对于92 mm厚，容重24 kg/m3的玻璃棉，使用灰铸铁作为质量块，并合理布置各个质量块的大小及其在玻璃棉中的相对位置可以有效提高隔声门在低频段的隔声性能；与普通隔声门相比，在低频段嵌入式质量隔声门的有效隔声量增加了5.0 dB。     

Mechanism and calculation of the niche effect in airborne sound transmission

The goal is to interpret and calculate the "niche effect" for the airborne sound transmission through a specimen mounted inside an aperture in the wall between the source and receiving reverberation rooms. The low-frequency sound insulation is known to be worse for the specimen placed at the center than for the specimen mounted at either edge of the aperture. As shown, the aperture with a tested specimen can be simulated at low frequencies as a triple partition where the middle element is the specimen and the role of the edge leaves is played by the air masses entrained at the aperture edges. With a centrally located specimen, such a triple system is symmetric and has two main natural frequencies close together. In this case, the resonant transmission is higher than for the edge arrangement simulated as a double system with one natural frequency. Analogous resonant phenomena are known to reduce the low-frequency transmission loss for symmetric triple windows or solid walls with identical air gaps and lightweight boards on both sides. The theoretical results obtained for the mechanical and acoustical models are in a good agreement with the experimental data.     

Noise control measures in the new Singapore International Airport

This paper describes some of the noise control measures incorporated in the passenger terminal building at the new Singapore International Airport at Changi. As the acoustics adviser to the Changi Airport Development Division of the Public Works Department, the overall consultant of this multi-billion dollar project, the author reviews some of the special steps taken to incorporate some of the latest acoustics techniques in this airport.These include the establishment of norms for various factors such as permissible background noise levels to each of the rooms, offices, arrival and departure halls, etc. Specifications called for include optimum sound absorption and reverberations times, airborne sound insulation for internal and external building partitions and structureborne sound insulation, as well as a sophisticated sound reinforcement system.Because of the stringent requirements following some of these specifications, the factor of the skill and workmanship of the contractors involved in the erection of the partitions had to be allowed for. As a result, all suppliers and contractors were requested to send their building proposals for testing. This was done in the newly established Acoustics Laboratory of the National University of Singapore at Kent Ridge. Some of the tests carried out, based on International Standards ISO R140 and ASTM E90 on sound transmission loss and ISO R354 and ASTM C423 on sound absorption, are evaluated.     

ACOUSTIC INSULATION PROVIDED BY A SINGLE WALL SEPARATING TWO CONTIGUOUS TUNNELS VIA BEM

This paper describes the computation of the acoustic insulation provided by a single simple wall separating two contiguous tunnels when a steady state, spatially sinusoidal, harmonic line load pressure excites one of the tunnels. The Boundary Element Method (BEM), formulated in the frequency domain, is used to compute the acoustic pressure in the two tunnels. The insulation conferred by the wall is characterized, identifying the location of insulation dips in the frequency domain with those dips related to its own natural dynamic vibration modes and those related to the natural vibration modes of the tunnels. This model is also used to assess how the dimension of the rooms, and the rigidity and thickness of the wall affect acoustic insulation. The transmission loss results obtained via the BEM are then compared with those provided by simplified analytical models such as the mass law.