瑞士布格多夫铁路桥降噪中使用弹性钢轨扣件的实验与理论分析本科毕业设计外文文献及译文

1、本科毕业设计外文文献及译文文献、资料题目：Structural Design of 文献、资料来源：网络文献、资料发表（出版）日期：2007.1院 （部）： xxx专 业： xxx班 级： xxx姓 名： xxx学 号： xxx指导教师： xxx翻译日期： xxxThe increased noise level as trains travel over bridges is, in many situations, a source of disturbance for nearby residents. As well as the rolling noise radiated by t

2、he wheel and track, the vibration generated at the wheel-rail interface also propagates into the bridge structure and the vibration response of the components of the bridge is an important extra source of noise compared with tracks at-grade. Vibration isolation of the bridge structure from the rail

3、is therefore used to reduce noise. This often takes the form of resilient rail fasteners. Two different elastic rail fastenings were therefore tested on a twin track bridge by the Swiss Railways (SBB). The bridge over the river Emme at Burgdorf, is a ballastless steel bridge with timbers between the

4、 rail fastener and the bridge. Hanging steel sleepers have been added between the wooden sleepers on which the track is supported to form a continuous deck under the track. To find the best elasticity for the rail fasteners, predictions of the bridge noisewere made using the Norbert model. Measureme

5、nts were made on the bridge with thetrack in its original state to provide parameters for the model. These included rail and sleeper vibration as well as pass-by noise from service passenger and freight trains at different speeds. For the two tracks, elastic rail fasteners from two suppliers were in

6、stalled. The measurement after installation showed a clear noise reduction for the frequency range from 80 to 400 Hz of about 10 dB. However the reduction in A-weighted overall noise level is in the range of 2 to 4 dB, as indicated by the model. The results show similar reduction for both systems.Th

7、e main reason for the increase in noise as trains cross a bridge is the vibration of the structure. Here the rolling noise radiated by the track and bridge is studied for the twin track bridge over the River Emme at Burgdorf, Switzerland. Two photographs of the 57m long bridge are shown in Fig 1. Th

8、e track on the bridge takes an unusual form in that steel sleepers have been added between the wooden sleepers on which the track is supported in order to form a continuous deck. The steel sleepers are hung from the rail and are not otherwise supported by the bridge structure.Resilient rail fastener

9、s were installed and the steel sleepers replaced with woodensleepers in October 2006. The reconstruction was accompanied with noise measure-ments in May, October, December 06 and January 07. One track was equipped with resilient fasteners from Pandrol, the other, from Vossloh. The elasticity of the

10、fasten-ers in both cases is about 20MN/m. To identify the effect of the hanging steel sleep-ers, additional noise measurements were carried out on one track after installing theresilient fasteners but before replacing the steel sleepers. To find the best elasticity for the rail fasteners, prediction

11、s of the bridge noisewere made using the ISVR software Norbert (Noise of Railway Bridges and ElevatedStructures) 1. Measurements were made on the track in its original state to provide parameters for the model. Fig. 1. Left: The Burgdorf bridge and track. Right: Arrangement of wooden bearing sleeper

12、s and suspended sleepers. ISVR has developed a bridge noise prediction model calledNorbert based on the combination of an analytical model of the track and a statistical energy analysis method (SEA) for the bridge 2, 3. In this method, the bridge structure is described using a single subsystem type;

13、 plates in bending. It has been found sufficient to use a simplified version of SEA which assumes equipartition of energy. In this assumption the energy is distributed to each of a number of subsystems according to their reso-nant energy capacity resulting in an estimate of the mean squared vibratio

14、n velocity on each susbsystem. For parts of the structure such as the wooden walkways to the side of the tracks on the Burgdorf Bridge, additional networks of subsystems can beadded to the model that are excited by the velocity of particular susbsystems of themain network. The bridge bearings and pi

15、ers are not important for the noise radiation. For the track, the rail support stiffness is an important parameter.The combined roughness of the wheel and rail running surfaces excites the wheeland rail into vibration according to their dynamic properties. Models for the rolling noise emitted by the

16、 wheel and track are well established 4, 5. The way in which the track is assumed to transmit energy to the SEA model of the bridge is an important aspect of the calculation. For the current bridge, a model of the rail coupled via a con-tinuous spring-mass-spring support to the longitudinal beam of

17、the bridge has been used up to the rail-on-sleeper resonance frequency. Above this frequency the forcefrom the track is assumed to drive the local input mobility of the longitudinal beam.The latter is based on an approximate formula for an I-section beam 6. The sound power is calculated from the vib

18、ration velocity of each component via simply calculated radiation ratios for each plate subsystem. Simple propagationcalculations are then used to estimate the sound pressure level at particular receiverlocations.The principles and results of the analysis were compiled in a report for Swiss Railways

19、 7. In the case of the Burgdorf Bridge, the steel sleepers will have a significant effecton the track decay rates and provide an additional radiating component. These effectshave been accounted for with a specially constructed track model. This includes the modal behaviour of the wooden and steel sl

20、eepers modelled as beams. The effect on the decay rates on noise is calculated as correction to the prediction (see 8).2.1 Parameters Derived from Measurements on the Bridge Using Service Trains Fig. 2(a) shows the measured vertical direct receptance at the rail-head. Although the measurement qualit

21、y is poor, especially below 300Hz, the main resonance peak due to the stiffness of the rail support can be clearly seen. The dashed line on Fig. 2(a) shows the calculated receptance using a support stiffness of 240MN/m and a mass per sleeper end of 28kg. In Fig. 2(b) the calculated decay rates are s

22、hown along with the decay rates measured by SBB according to the method described in reference 8. In the measurements of the decay rate responses up to a distance of 7.2m from the excitation have been used. The minimum decay rate measureable with this length of baseline is 0.6dB/m 8. The measured de

23、cay rate is well above this. Fig.2.Comparison of measurement and calculation: left side, vertical point receptance of the rail; right side, decay rates of the rail.An estimation of the combined effective roughness (i.e. combined wheel and rail roughness with the contact filter already accounted for)

24、 is needed for the predictions. A method to determine the combined roughness from rail vibration measurements under traffic is described in reference 9. This method uses the spectrum of vibrationduring a train pass-by and three correction factors. It has been applied to rail vibration measured by th

25、e SBB. The roughness is a function of the brake type of the train. Here, the most important trains to consider are the cast iron block tread-braked freight trains. Two measurements of vertical rail vibration are available from trains travelling at steady speeds of 77km/hr and 72km/hr. Three more are

26、 available for lower speeds that vary during the measurements from about 40 to 60km/hr. The estimates of the combined effective roughness from these records are presented in Fig. 3. They are plotted as a function of frequency corresponding to a train speed of 100km/hr. These roughness spectra are pl

27、otted in comparison with the typical spectra for smooth rail and either cast iron block tread-braked, or disc-braked trains. These are the standard roughness spectra used in the Silent Freight and Silent Track EU projects 10. The roughness assumed for the present calculations is also shown on Fig. 3

28、.Fig. 3. Combined effective roughness spectra derived from measurements compared with those used in the Silent Freight and Silent Track Projects (, calculated from the two faster freight trains; - - - -, calculated from the slower freight trains - - - , SF/ST project combined roughness for tread bra

29、ked and (lower) for disc braked wheel; mean spectrum assumed for current calculations)The microphone positions were, for both tracks: beneath the bridge; 7.5m to the side, 1.2m above the rail head and 25m to the side, 2m above the rail head. These were all in a plane 6m from one end of the bridge. A

30、n additional measurement was made in the 7.5m position adjacent to the track at grade. The details of the measurements can be found in a report 11 for Swiss Railways.Both freight and passenger trains were measured. Only freight trains fully equipped with cast iron brakes are included. All passenger

31、trains were either equipped with composite-block or disc brakes. All passenger trains stopped at the nearby station of Burgdorf resulting in a large range of velocities and some changes of velocity (up to20% in some cases) during measurement. Fig. 4 presents the measurements and predictions for the

32、freight trains for the north and south tracks before and after the installation of the resilient baseplates. Fig. 5 presents the corresponding measurement results for the passenger trains. No predictions were made for the passenger trains. The measurements are the average of freight trains travellin

33、g between 66 and 72km/hr in each case. The predictions are the nearest available at 80km/hr. It can beseen that both baseplate types perform similarly resulting in 5 to 10dB reduction of noise in the 80Hz to 400Hz one-third octave frequency bands. However, around thepeak of the noise spectrum near 5

34、00Hz, smaller reductions are achieved. It is at this frequency and above that the rail noise dominates over the bridge-structure radiatednoise. At 1.6kHz and above the wheel is the dominant noise source and there is very little variation before and after the change was made to the track.Additionally

35、, Fig. 4(a) shows the mean of measurements on the track at-grade. These were made at the slightly lower average speed of 60 km/hr. The noise from thewooden sleepers, which was identified by Twins modelling 7 to dominate below 800Hz, is in this case baffled by the ballast and the ground reflection is

36、 expected to be fairly absorbing. This is in contrast to the open bridge structure and the reflection of the water surface. Additionally there is no control of the rail roughness accounted for in the comparison. Despite these differences, it can be observed that the bridge noise has been lowered to

37、levels similar to those of the at-grade track in the frequency bands up to 250Hz. The rail noise component is clearly much lower from the at-gradetrack than from the bridge (800Hz to 1.25kHz).Fig. 4. Comparison of predictions with measurements of average of freight trains; (a) north track; (b) south

38、 track (, measured before; , measured after, , predicted before; - - -, predicted after, (a) measured at at-grade track, (b) measured at the bridge with the steel sleepers and resilient baseplates)Fig. 5. Average of measurements of passenger trains; (a) north track; (b) south track (, before; - - -,

39、 after, right graph, measured at the bridge with the steel sleepers still in place but with resilient baseplates installed)Fig. 4(b) presents the noise measured when the resilient baseplates had been in-stalled but the steel sleepers had not yet been replaced. It shows that the reductionachieved by

40、the baseplates in the 80 to 400Hz range is compromised by the steel sleepers by around 2 to 3dB.The results for the passenger trains shown in (Fig. 5) indicate the same trends as the freight trains. The 1kHz peak in the spectrum of noise from the south track is probably equipment noise from the trai

41、ns travelling in this direction. The bridge is shown to give much higher levels of noise than nearby track at grade. The installation of resilient baseplates has reduced the overall level difference from about 11dBA to about 8dBA. However, the baseplates make of greater noise reduction of 5 to 10dB

42、where the bridge structure-radiated noise dominates between 80 and 400Hz. The Norbert model has predicted the reduction in noise in the 80 400Hz bands reasonably well although the measured spectra are smoother than those predicted. In the 630 and 800Hz bands, where the rail noise dominates,Norbert h

43、as predicted a reduction that is greater than that actually achieved. This leaves the overall noise reduction to be only about 3dB (4dB predicted) for the freight and passenger trains alike. The removal of the hanging steel sleepers was worthwhile to gain the full benefit of the structure noise redu

44、ction Promising locations for similar bridge treatments will be identified according to their cost benefit. The baseplates from different suppliers to the same specification produce similar results.The authors are grateful to the SBB for permission to publish this work.1Bewes, O.G., Thompson, D.J.,

45、Jones, C.J.C., Wang, A.: Calculation of noise from railway bridges and viaducts: Experimental validation of a rapid calculation model. Journal of Sound and Vibration 293, 933943 (2006) 2Janssens, M.H.A., Thompson, D.J.: A calculation model for the noise from steel railway bridges. Journal of Sound a

46、nd Vibration 193, 295305 (1996) 3Harrison, M.F., Thompson, D.J., Jones, C.J.C.: The calculation of noise from railway viaducts and bridges. Proc. Institution Mechanical Engineers, Part F (Journal of rail and rapid transit) 214, 125134 (2000) 4Thompson, D.J., Hemsworth, B., Vincent, N.: Experimental

47、validation of the TWINS prediction program for rolling noise, part 1: Description of the model and method. Journal of Sound and Vibration 193, 123135 (1996) 5Thompson, D.J., Jones, C.J.C.: A review of the modelling of wheel/rail noise method. Journal of Sound and Vibration 231(3), 519536 (2000) 6Bew

48、es, O., Thompson, D.J., Jones, C.J.C.: Calculation of noise from railway bridges: The mobility of beams at high frequencies. Structural dynamics: Recent advances. In: Proceedings of the 8th International conference, Institute of Sound and Vibration Research, Southampton, (paper 64 on CD ROM) July 14

49、16 (2003) 7Jones, C.J.C., Thompson, D.J.: Acoustic analysis of Burgdorf bridge, ISVR contract report no 06/03, University of Southampton (2006) 8Jones, C.J.C., Thompson, D.J., Diehl, R.J.: The use of decay rates to analyse the performance of railway track in rolling noise generation. Journal of Soun

50、d and Vibration 293(35), 485495 (2006) 9Janssens, M.H.A., Dittrich, M.G., de Beer, F.G., Jones, C.J.C.: Railway noise measurement method for pass-by noise, total effective roughness, transfer functions and track spatial decay. Journal of Sound and Vibration 293(3-5), 10071028 (2006) 10Bouvet, P., Vi

51、ncent, N., Coblenz, A., Demilly, F.: Optimisation of resilient wheels for rolling noise control. Journal of Sound and Vibration 231(3), 765777 (2000)11Muff, W., Grolimund & Partner AG, SBB Stahlbrcke Burgdorf, Lrmmessungen vor und nach der Sanierung, Bern (2007) B.Schulte-Werning et al.(Eds.):Noise

52、and Vibration Mitigation,NNFM99,pp.208-214,2008. Springer-Verlag Berlin Heidelberg2008中文译文:瑞士布格多夫铁路桥降噪中使用弹性钢轨扣件的实验与理论分析京都议定书Kstli1，联席会议Jones2，瑞士和DJ Thompson1联邦铁路SBB, I-FW-PS, Schanzenstr. 5 CH-3000 Bern 65, 瑞士电话：+41（0）51 220 4699传真：。+41（0）51 220 5014kornel.koestli sbb.ch2南安普敦，ISVR，海菲尔德南安普敦，SO17 1BJ大

53、学南安普敦，UK电话：+44（0）2380 593224，传真：。+44（0）2380 593190cjcjisvr.soton.ac.uk综 述在大多情况下，当火车从桥上通过时，增加的噪声水平就成为了对附近居民的干扰源。车轮和轨道发出的滚动噪声，以及轮轨接口处产生的振动在桥的结构中传播。与地面轨道相比，桥的部件的震动响应成为了另一个重要的噪声源头。因此，从铁路桥梁结构的隔震被用来降低噪声，往往为弹性钢轨扣件的形式。因此，由瑞士铁路（国铁）在双轨的桥梁上对两种不同的钢轨扣件进行了测试。横跨布格多夫的艾蒙河的桥梁，是一座无碎石钢桥，轨道扣件和桥梁之间使用了木质材料。吊钢枕木被添加在支撑着轨道的木

54、质枕木之中，以便在轨道下形成一个连续甲板。为了找到最佳弹性的铁路扣件，借助诺伯特模型，桥梁噪声被进行了预测。测量是在拥有原始状态的轨道的桥梁上进行的，来为模型提供参数。其中包括铁路和轨枕振动，以及来自以不同速度经过的客运和货运列车的噪声。来自两个供应商的钢轨扣件被安装了在了两个轨道。安装后的测量结果显示频率范围从80到400赫兹的噪声明显降低了约10 分贝。然而，如模型所示，在A -加权的总噪声水平下降的范围是在2至4分贝。结果表明这两个系统噪声降低情况类似。1 简介火车穿过大桥时，噪声上升的主要原因是结构的振动。下面是研究了横跨在瑞士布格多夫的艾蒙河上的双轨桥梁的轨道和桥梁的滚动噪声辐射。图

55、1为这座57米长的桥的两张照片。桥的轨道中，钢材被加在支撑轨道的枕木之间以形成一个连续的甲板木轨枕补充。钢铁轨枕吊在铁路，不另行被桥梁结构支撑。2006年10月弹性钢轨扣件被安装，钢材枕木取代木质枕木。重建与噪声测量进行于5月，10月，12月6日和1月7日。一条轨道被装备来自Pandrol的弹性扣件，另一条的来自Vossloh。在这两种情况下扣件的弹性约为20MN /米。要确定悬钢的效果，在安装弹性扣件之后，更换钢轨枕之前，需进行额外的噪声测量。为了找到最佳弹性的铁路扣件，使用ISVR软件诺伯特（噪音和高架铁路桥梁结构）进行了桥梁噪声预测1。测量了在其原始状态的轨道，为模型提供参数。图. 1.

56、左图: 布格多夫桥与轨道。 右图:木枕与钢枕的安装。2 建模ISVR开发了桥梁噪声预测模型诺伯特，该模型以一个对轨道的分析模型和一个桥梁统计能量分析法的 2，3（SEA）组合为基础。在此方法中，桥梁结构被用一个单独的子系统类型描述，板弯曲。人们已经发现足以使用的海简化版本，承担能量均分。在这个假设中，能量根据自己的谐振能量的最大承受力被分配给每一个子系统，从而导致对每个子系统平均每平方振动速度的估计。对于结构部件，如在布格多夫大桥上的铁轨旁的木制人行道，其他子系统的网络可以被添加到一个模型，该模型被主要网络的特别子系统的速率刺激。桥梁支座和桥墩对于噪声射辐都不重要。对于轨道，是一个重要参数。根

57、据其动态特性，车轮轨道运行表面粗糙度激发振动。车轮与轨道发出滚动噪声的模型被完美确立4，5。一个轨道被假设将能量传送到跨海大桥模型的方法是计算的一个重要方面。对于目前的大桥，一个通过连续的弹簧质量弹簧来支持桥梁纵梁的铁路模型已经被使用到轨上枕木共振频率。超过这个频率来自轨道的力被假定驱动本地纵梁流动性的输入。后者为基于一个I型桥梁的近似计算公式6。声功率是由每个组件的振动速度通过简单计算每盘子系统的辐射率可得。简单传播的计算，然后被用来估计在特定接收地点的声压水平。原则和分析结果，被编译于一份瑞士铁路报告中。就布格多夫大桥而言，钢枕木将对轨道噪声衰减率有显著影响，并为其提供一个额外的散热元件。这些影响已用一个专门建造的轨道模型说明解释。这包括木轨枕和钢轨枕为桥梁的模态行为。对噪声衰退率的影响被计算作为预测的校正（见8）。8中描述的方法SBB测量得到的衰退率被呈现出来。在衰退率的测量中，远达7.2米激发距离已被使用。使用这一基线长度，衰退率可测最低值为图2：比较测量和计算路衰变率：左侧为铁路垂直接收点;右侧为铁路衰变率。对预测来说，一个对有效粗糙结合的估计是必要的。一个用来确定交通繁忙时来自铁路振动测量的结合粗糙度的方法为文献9中所描述。此方法利用一辆火车经过时的振动光谱和三个校正因子。它已被SBB应用到铁路的振动的测量。中，所有客运列车停在了布格