| 1. |
- Amiryarahmadi, Nata, 1982, et al.
(författare)
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Time-domain model of a tapping machine
- 2011
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Ingår i: Proceedings - 6th Forum Acusticum 2011, Aalborg, 27 June - 1 July 2011. - 2221-3767. ; , s. 1713-1718
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Konferensbidrag (refereegranskat)abstract
- In the past few years the use of lightweight buildings made of prefabricated wooden elements has become more common. Ease of installation, high accuracy and lightness of such buildings has attracted builders and designers. Sweden, having a large coverage of renewable forests has an increasing interest in multi-storey wooden buildings. However noise and vibration in wooden buildings is an issue of concern especially low frequency impact sound due to footsteps. Impact sound insulation of floors can be measured based on ISO 140-7 using standardized tapping machine as excitation source. Experience has shown that in many cases the results obtained by this method do not correlate with annoyance experienced by inhabitants. On the other hand, the method presented in ISO 140-7 has usually shown to be relevant for the evaluation of impact sound transmission of concrete floors. Discovering the source of this contradiction requires deeper understanding of the impact process. A first step would be to find the difference between contact forces of the tapping machine on different floor materials. One could then correlate it with inhabitants’ perceived annoyance. This paper is the first step of this investigation which is a part of a Swedish research project called AkuLite. In this work a time-dependent model based on Hertz’s contact law is presented for the tapping machine. The model is validated by measurements on a homogeneous concrete floor. Also the contribution of parameters such as damping and stiffness of floor material on the resulting impact force and vibrations is studied.
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| 2. |
- Andersson, Patrik, 1974, et al.
(författare)
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Numerical Modelling of Tyre/Road Interaction
- 2012
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Ingår i: Scientific Bulletin, Automotive Series. - 1453-1100. ; 22
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Tidskriftsartikel (refereegranskat)abstract
- From November 2012 all passenger car tyres, light truck tyres and heavy duty vehicle tyres sold on the aftermarket in the European Union must have a label classifying the external rolling noise, the fuel efficiency, and the wet grip. This regulation puts a focus on optimisation of the tyre design with respect to all these parameters at once. Up to today these three parameters have been treated rather independently. There is little to no detailed information available on the relationship between rolling noise generation, rolling resistance, and grip of car tyres besides empirical data based on measurements. Today, simulation models that can simulate all these effects at once have just started to emerge. This paper gives a brief presentation of the past and the most resent development of numerical tyre/road interaction models with focus on external noise, rolling resistance, and grip. Today, the simulation models can be used to gain fundamental knowledge about the tyre/road interaction process and the resulting noise, rolling resistance, and grip. Models for combined optimisation of rolling resistance and noise emissions exists, and are just about to be used in preliminary investigations. Models that in addition give results for grip are still under development.
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| 3. |
- Andersson, Patrik, 1974, et al.
(författare)
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Numerical Modelling of Tyre/Road Interaction
- 2011
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Ingår i: Exploratory Workshop: Modern Methods of Vibro-Acoustic Studies With Automotive Applications, University of Pitesti, Romania, November 24-25, 2011.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- From November 2012 all passenger car tyres, light truck tyres and heavy duty vehicle tyres sold on the aftermarket in the European Union must have a label classifying the external rolling noise, the fuel efficiency, and the wet grip. This regulation puts a focus on optimisation of the tyre de- sign with respect to all these parameters at once. Up to today these three parameters have been treated rather independently. There is little to no detailed information available on the relationship between rolling noise generation, rolling resistance, and grip of car tyres besides empirical data based on measurements. Today, simulation models that can simulate all these effects at once have just started to emerge. This paper gives a brief presentation of the past and the most resent develop- ment of numerical tyre/road interaction models with focus on external noise, rolling resistance, and grip. Today, the simulation models can be used to gain fundamental knowledge about the tyre/road interaction process and the resulting noise, rolling resistance, and grip. Models for combined opti- misation of rolling resistance and noise emissions exists, and are just about to be used in preliminary investigations. Models that in addition give results for grip are still under development.
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| 4. |
- Beckenbauer, Thomas, et al.
(författare)
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A mixed physical and statistical approach for the prediction of tyre/road noise
- 2013
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Ingår i: Proceedings of AIA-DAGA 2013 Conference on Acoustics, Meran, Italy, March 18-21, 2013.
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Konferensbidrag (refereegranskat)abstract
- The hybrid approach is intended to make a tool available for both analysis of tyre/road noise depending on road surface characteristics and synthesis of low noise road surfaces. However, the model does not claim applicability for the development of low noise tyres. Basic physical models for the calculation of non linear contact forces and tyre vibrations as well as an empirical model for the aerodynamic tyre/road noise generation have been implemented in order to feed a multiple regression model with problem specific input quantities. The model is able to predict absolute coast-by noise levels in terms of third octave bands between 315 Hz and 2 kHz within a wide speed range from 50 km/h up to 120 km/h separately for different noise generation mechanisms. Despite the fact that the model does not perform better than +/- 1 dB concerning the difference between calculated and measured overall noise levels and +/- 5 dB for spectral level differences it provides relevant information on the distribution of sound energy due to mechanical and aerodynamic processes within the tyre/road contact. This affords opportunity to characterize and develop road surfaces yielding reduced excitation of rolling noise which is presented by means of practically relevant examples.
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| 5. |
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| 6. |
- Bein, Thilo, et al.
(författare)
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Integrated Solutions for Noise & Vibration Control in Vehicles
- 2012
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Ingår i: Procedia - Social and Behavioral Sciences. - : Elsevier BV. - 1877-0428. ; 48, s. 919-931
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Tidskriftsartikel (refereegranskat)abstract
- A strong issue on the development of new vehicles is the weight reduction, required for the reduction of the fuel consumption and the CO2 emissions. The current vehicles have already a structure optimised to have low weight without reducing the required performances. However, there are some components of the structure that can be further reduced in weight still matching the resistance, crash and fatigue performances, but giving a poor performance in terms of noise and vibrations and increasing both the structure-borne and air-borne sound transmission.In the European FP7 project Green City Car, flexible, integrated passive and active solutions are developed permitting noise and vibration attenuation in vehicles equipped with the next generation of highly fuel-efficient two- or three cylinder internal combustion engines (ICE). Among others, shunted piezoelectric patches and electro-magnetic actuation as well as smart Helmholtz resonators are considered. Additionally, dedicated active noise control systems for the control of broadband rolling noise are developed. Besides, Green City Car addresses and implements novel damping materials and acoustic treatments as well as design approaches for tyres which are an important acoustic source for exterior and interior noise. This holistic approach should lead to a reduction in noise and vibrations levels in the order of 10 dB(A) and more measurable in the city car provided (not on component level). Currently, Green City Car finished its second year and first results are presented and discussed in this paper.
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| 7. |
- Buckers, C., et al.
(författare)
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Analysis of the acoustic characteristics and optimization potential of road surfaces - One focus within the project "Quiet Road Traffic 3"
- 2012
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Ingår i: 41st International Congress and Exposition on Noise Control Engineering 2012, INTER-NOISE 2012; New York, NY; United States; 19 August 2012 through 22 August 2012. - 9781627485609
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Konferensbidrag (refereegranskat)abstract
- The development of silent road surfaces demands a detailed analysis of the tire/road interaction mechanisms basically determining the noise radiation of flowing traffic. Such an analysis is of significant importance to identify and characterize the relevant effects which affect the acoustic properties of the pavements. This paper reviews the approaches pursued within the interdisciplinary research project "Quiet Road Traffic 3" including an adequate expansion of the SPERoN model for the quantitative prediction of the tire/road noise. A variety of novel materials and road constructions is investigated to validate the model, to design optimized pavements, and to explore their application potential. The practical use of the results will be finally checked by implementing and monitoring test tracks. The research activities cover asphalt as well as concrete construction techniques and focus in particular on measures to reduce the noise nuisance in agglomerations. In total, the approaches within the project "Quiet Road Traffic 3" are intended to lower the road traffic noise level by 4 to 6 dB(A) as compared to the current state of the art.
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| 8. |
- Estévez Mauriz, Laura, 1982, et al.
(författare)
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Incorporation of the quiet side in noise maps
- 2014
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Ingår i: TECNIACUSTICA 2014. 45st SPANISH CONGRESS ON ACOUSTICS. 8 th IBERIAN CONGRESS ON ACOUSTICS. EUROPEAN SYMPOSIUM ON SMART CITIES AND ENVIRONMENTAL ACOUSTICS. - 2340-7441. - 9788487985256 ; , s. 123-130
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Konferensbidrag (refereegranskat)abstract
- Nowadays noise maps are focused on the noise level at the most exposed façade, leading to underestimations on the shielded areas. Previous research showed that quiet areas have positive effects for the inhabitants' quality of life. To solve this problem, an engineering method was developed within the QSIDE project. This method aims to improve noise maps in terms of multiple reflections in an efficient way. Two different terms, attenuation due to the barrier and the canyon will be incorporated. In this paper, the suggested model from QSIDE has been further developed for its inclusion in noise map calculations.
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| 9. |
- Forssén, Jens, 1968, et al.
(författare)
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Introduction to traffic noise abatement
- 2014
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Ingår i: Environmental Methods for Transport Noise Reduction. - : CRC Press. ; , s. 1-18
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Presents Evidence-Based Guidance on Noise Abatement Methods Solutions for reducing the noise impact of road and rail traffic can be found in the use of natural elements in combination with artificial elements in urban and rural environments. Ground and road surface treatments; trees, forests, and tall vegetation; and the greening of buildings and other surfaces can contribute to powerful and cost-effective noise reduction. Environmental Methods for Transport Noise Reduction presents the main findings of the Holistic and Sustainable Abatement of Noise by optimized combinations of Natural and Artificial means (HOSANNA) research project. This project involved experts from seven countries, and assessed noise reduction in terms of sound level reductions, perceptual effects, and cost–benefit analysis. It considered a number of green abatement strategies, and aimed to develop a toolbox for reducing road and rail traffic noise in outdoor environments. Combines Theory with Practice Broad in both theory and application and based on leading-edge research, the book brings together the findings and their practical use. It details assessment methods for perceived noise, and outlines noise prediction methods that can be integrated with noise mapping software. It also explores the economic benefits and positive effects on urban air quality and CO2 levels. The material is this book: Includes up-to-date results on noise mitigation using vegetation and ground treatments Contains relevant results on innovative noise barrier designs Presents data on acoustic performance of vegetation and soil substratum Provides perceptual and cost–benefit analyses of noise mitigation methods Environmental Methods for Transport Noise Reduction is a helpful guide for noise consultants, city planners, architects, landscape architects, and researchers.
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| 10. |
- Forssén, Jens, 1968, et al.
(författare)
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Modelling the interior sound field of a railway vehicle using statistical energy analysis
- 2012
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Ingår i: Applied Acoustics. - : Elsevier BV. - 0003-682X .- 1872-910X. ; 73:4, s. 307-311
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Tidskriftsartikel (refereegranskat)abstract
- The sound field in train compartments, treated as a series of connected air cavities, is modelled using statistical energy analysis, SEA. For the case under study, with five cavities in series and the source in the second cavity, a closed-form solution is obtained. An adjusted SEA model is used to predict the rate of spatial decay within a cavity. The SEA model is validated using results from a ray tracing method and from scale model measurements. For the octave bands 500-4000 Hz, good agreement is shown between the results from measurements, the ray tracing and the SEA model, for the two saloons closest to the source cavity (a vestibule). The SEA model was shown to slightly underestimate the rate of spatial decay within a cavity. It is concluded that a reasonable cause is the additional diffusion due to the seating.
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