| 1. |
|
|
| 2. |
|
|
| 3. |
- Orrenius, U., et al.
(författare)
-
Attractive train interiors : Minimizing annoying sound and vibration
- 2014
-
Ingår i: Noise and Vibration Mitigation for Rail Transportation Systems. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783662448311 - 9783662448328 ; , s. 707-714
-
Konferensbidrag (refereegranskat)abstract
- A study of annoying sounds and vibrations generated by train interiors is reported. Different types of annoying sounds are discussed with respect to the effects they have on the passengers and a notation for distinguishing annoying sounds on trains is defined. A survey of disturbing sounds and interior vibrations on Swedish intercity trains is also reported. A large majority of the annoying sounds found in the survey were of tapping or rattling character, originating from components like ceiling panels, light covers, cabinet doors, interior sliding doors and foldable tables. For some vehicles the number of annoying sounds and vibration issues related to interiors is substantial also for cars with only a few years in operation. This observation underlines the need for systematic abatement procedures and proactive measures from the manufacturers and operators to ensure comfortable train journeys. A review of processes applied in the automotive sector to control annoying noises is also summarized and opportunities for knowledge transfer to the railway industry are discussed. Finally, best practice design solutions to reduce interior vibrations and annoying sounds from train interiors are summarized in view of the results of the present survey and previous vehicle design experience.
|
|
| 4. |
- Orrenius, U., et al.
(författare)
-
Prediction and control of sound transmission through honeycomb sandwich panels for aircraft fuselage and train floors
- 2010
-
Ingår i: 17th International Congress on Sound and Vibration 2010, ICSV 2010. - 9781617822551 ; , s. 117-124
-
Konferensbidrag (refereegranskat)abstract
- Composite sandwich structures with honeycomb cores are increasingly considered as an alternative to aluminium for aircraft fuselages. Technical benefits include lower density, higher strength and greater fatigue resistance. The ability of composite materials to inexpensively be formed into complex shapes allows part count reductions and substantial cost savings. For railway carbodies, metal honeycomb sandwich panels are common in door panels and for interior floors. For floors the drivers are low weight, good moisture properties, fire resistance combined with high stiffness. Despite these advantages, sandwich structures may exhibit increased sound transmission compared to homogenous structures. Appropriate choice of core materials will reduce the need for subsequent noise control measures. In this paper it is shown how a physical understanding for the wave transmission phenomena together with modern prediction software, can be used to achieve designs that satisfy both acoustical and structural requirements. Calculated wavenumbers and transmission losses are compared to measurements for composite sandwich panels with honeycomb cores, treated and un-treated with damping layers. Modeling concepts as well as the potential for insertion losses due to added damping are discussed.
|
|
| 5. |
- Orrenius, U., et al.
(författare)
-
Rail vehicle source assessment within a virtual certification process
- 2014
-
Ingår i: PROCEEDINGS OF INTERNATIONAL CONFERENCE ON NOISE AND VIBRATION ENGINEERING (ISMA2014) AND INTERNATIONAL CONFERENCE ON UNCERTAINTY IN STRUCTURAL DYNAMICS (USD2014). - 9789073802919 ; , s. 3511-3525
-
Konferensbidrag (refereegranskat)abstract
- The present paper aims at giving an overview of the vehicle noise source modelling work carried out within the Acoutrain FP7 European research project. Results are presented for several areas including: equivalent source modelling concept applied to typical train sources, component based models for aero-acoustic noise generation of pantographs and installation effects of bogie and roof mounted sources. A process to characterize vehicle noise sources in an industrial context is presented. It is shown that equivalent monopole models, for which the source is described by a few monopoles, can be applied to represent real vehicle sources. It is also displayed how analytical models can be used to calculate the insertion loss of screens for sources that can be represented by point sources. Ray tracing and energy BEM models are used to determine the high frequency installation effect of a source in the bogie and a practical, procedure for in-situ testing of installation effects is suggested. For high speed applications a component based model is shown to accurately represent the spectrum of a train pantograph. It is concluded that the results to date are promising but more work is needed to validate the proposed process and methods for real vehicle installations in terms of modelling accuracy and usability in a virtual testing framework for TSI certification purposes.
|
|
| 6. |
- Orrenius, U., et al.
(författare)
-
Sound transmission through a high-speed train roof
- 2011
-
Ingår i: 18th International Congress on Sound and Vibration 2011, ICSV 2011. - 9781618392596 ; , s. 2392-2399
-
Konferensbidrag (refereegranskat)abstract
- Low internal noise in train carriages is of great importance to the comfort of the passengers, and accordingly also for train manufacturers and operators who want to keep a comfort advantage in relation to other means of transportation. With increased speed the aerodynamic noise becomes an important contributor. Here a train roof section is studied containing a recess where a pantograph is mounted. Significant excitation is present both from aerodynamic forces directly acting on the roof as well as forces transmitted via the pantograph structure and the power input to the compartment is studied for speeds up to 350 km/h. The train roof was modeled using a hybrid FE-SEA approach with input excitation data from transient and compressible CFD calculations as well as from measured structural forces from a full scale wind tunnel test. For reference, turbulent boundary layer (TBL) excitation was studied using a Corcos model. For the transmission model the outer roof structure is described by FE whereas the interior parts are represented by statistical subsystems. Experimental validation of the approach was made on an existing train. The result indicates that for the configuration and sources analysed the contributions to the interior noise from all three sources analysed are significant. Ranking of transmission paths into the train interior and perspectives for application of such models for parametric studies of design parameters are discussed.
|
|
