| 1. |
- Andersson, Patrik, 1974, et al.
(författare)
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A Method for Experimental Collection of Global Material Data for Tyres
- 2001
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Ingår i: Nordic Vibration Research 2001, Stockholm, Sweden (The Scandianvian Vibration Society, www.svib.se).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- For the modelling of the dynamic behaviour of tyres material data are required. Depending on the character of the model these will have different quality. Modelling with global structures such as beams or plates, representative data for the global bending stiffness, global mass etc. are needed. These data do not represent the details of the tyre structure but the combined properties of the structure. Therefore it is not possible to cut out samples of the tyre and determine the global material properties by measurements on these samples. Consequently it is necessary to estimate the material parameter by measurements carried out on the complete tyre. Results from such measurements will be related to the model used for the tyre (e.g. ring model, orthotropic plate, etc.). The material data obtained in such way are consequently a function of both the tyre structure and the model, which is used to update the data. A method for experimental collection of global material data for tyres has been developed. This method is based on the experimental characterisation of tyres by driving point and transfer mobilities and the use of the orthotropic plate tyre model for updating the material data.
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| 2. |
- Andersson, Patrik, 1974, et al.
(författare)
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A study of forces and noise generation in a contact including adhesive bonds
- 2004
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Ingår i: Nordic Vibration Research 2004, June 3-4, (The Scandinavian Vibration Society, www.svib.se).
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Konferensbidrag (refereegranskat)abstract
- Paper to be published.Adhesive forces are present in the contact between a road surface and a rolling tyre. Theses forces may add up to substantial adherence forces, causing stick-snap excitation of tread blocks, high frequency noise generation, and increased rolling resistance. An experimental setup was designed to study the process when a tyre tread block sample was pressed onto a road surface sample, and hastily removed. Time variation of contact forces and sound pressure were measured. The same situation was modelled using a time domain model of two elastic bodies in non-linear dynamic contact. The contact area is spatially discretised in contact points and the contact problem is solved using an elastic half-space. The response of the block is calculated by convoluting the forces with pre-calculated impulse responses of the same block, which is modelled as a mass-spring system. The adhesive bounds are included by allowing negative contact forces; the contact at a point breaks when the calculated contact force reaches a specified negative value. Typical results from the experimental setup and the model are presented. It is concluded that the experimental setup is suitable for investigating the detachment process of the tread block and that the model is able to qualitatively capture the contact force and noise generation.
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| 3. |
- Andersson, Patrik, 1974, et al.
(författare)
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Experimental Study of High Frequency Response of Tyres
- 2003
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Ingår i: EuroNoise2003, May 19-21 2003, Naples, Italy.
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Konferensbidrag (refereegranskat)abstract
- Most traditional tyre models concern the low and middle frequency ranges. It is necessary to include higher frequencies for improved accuracy in tyre/road interaction models. Often only the radial direction is included, although the tangential direction may be important, especially studying stick slip motion in the contact between tyre and road surface. Designing models requires insight into the behaviour of the tyre structure at higher frequencies. To add insight of high frequency behaviour, experimental studies were done on four different tyres with the same internal design but with different tread patterns. The results of this study underline the importance of the local deformation when forces act with small excitation areas on the tread. Adequate consideration of the tread properties in the tyre/road interaction models is thus of importance to obtain the correct local contact force distribution. This is most important for the tangential driving point mobility. Tread patterns are shown mainly to modify the flexural stiffness and mass in comparison to smooth tyres, while block resonances are not expected to be located in the frequency range in which tyre/road noise is important.
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| 4. |
- Andersson, Patrik, 1974, et al.
(författare)
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High Frequency Dynamic Behaviour of Smooth and Patterned Passenger Car Tyres
- 2004
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Ingår i: Acta Acustica united with Acustica. - 1610-1928 .- 1861-9959. ; 90:3, s. 445-456
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Tidskriftsartikel (refereegranskat)abstract
- Most traditional tyre models concern the low and middle frequency ranges. For improved accuracy in tyre/roadinteraction models it is necessary to include higher frequencies. Often only the radial direction is included, althoughthe tangential direction may be important, especially studying stick slip motion in the contact between tyreand road surface. Designing accurate and efifcient models requires insight into the behaviour of the tyre structureat higher frequencies to make the models as complete as necessary without creating tools that are computationallytoo costly. To add insight to this area, experimental studies were done on four different tyres with the sameinternal design but with different tread patterns. Point mobilities were measured and compared with two differenttyre models, a two-layer plate model based on the elastic field equations and an orthotropic plate model. Theresults of this study underline the importance of the local deformation when there are forces that act with smallexcitation areas on the tread. Adequate consideration of the tread properties in the tyre/road interaction modelsis thus of extreme importance to obtain the correct local contact force distribution. This is most important for thetangential driving point mobility. Tread patterns are shown mainly to modify the flexural stiffness in comparisonto smooth tyres, while block resonances are not expected to be located in the frequency range in which tyre/roadnoise is important.
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| 5. |
- Andersson, Patrik, 1974, et al.
(författare)
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Investigation of Driving Point and Transfer Mobilities of Simple Tread Blocks on a Tyre
- 2001
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Ingår i: 17th International Congress on Acoustics, Rome, Italy, 2001.
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Konferensbidrag (refereegranskat)abstract
- An important issue when modeling noise generation from rolling tyres using the orthotropic plate tyre model [1] is to find accurate Green’s functions for the responses of the tyre. These Green’s functions are used to solve the tyre/road contact problem of the rolling tyre in the time domain. For tyres with tread blocks, it is important to consider the influence of the tread blocks on the response. It has previous been suggested that the tread blocks could be modeled as mass-spring systems [2]. Measurements of mobilies on a tyre with simple and regular tread blocks shows that this approach is unnecessary when modelling the response in radial direction of the tyre in the frequency range between 0 and 2500 Hz. Instead the tyre may be modeled, using a plate tyre model, as a soft plate with slightly higher local deformation. The tread pattern may be modeled in the tyre/road contact model as a macro roughness, where points at the blocks may be in contact with the road while forces at points in the groves are set to zero.
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| 6. |
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| 8. |
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| 9. |
- Kropp, Wolfgang, 1959, et al.
(författare)
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Simulation of the Tyre/Road Noise
- 2001
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Ingår i: Styrian Noise, Vibration & Harshness Congress 2001, Acoustic Competence Center, Graz, Austria.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Kropp, Wolfgang, 1959, et al.
(författare)
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The failure of traditional traffic noise control for quiet areas
- 2004
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- One can consider the acoustic soundscape as consisting of two parts the direct acoustic soundscape and the diffuse acoustic soundscape. This fact has important consequences when attempting to change the acoustic soundscapes. The traditional approach to control traffic noise by means of noise barriers or change of traffic distribution is only valid for the areas directly exposed from sources (direct acoustic soundscape). These areas will experience a certain decrease of sound pressure levels when applying these noise control measures. However there will be a lower limit for reduction due to the presence of a diffuse acoustic soundscape. To control/modify such a diffuse acoustic soundscape has been shown very difficult by traditional means of noise control. Main characteristic of diffuse acoustic soundscapes is the presence of a multitude of sources, distributed over a wide area contributing evenly to the acoustic soundscape in a certain areas. Screening will only lead to a redistribution of sound, however consequences of such a redistribution will not be recognised in a diffuse sound field. Absorption has been identified as a main parameter to control diffuse acoustic soundscapes. Reducing sound pressure levels in shielded areas such as inner-yards can only be achieved by adding acoustically absorbing areas along the transfer path between source and receiver, but especially inside the inner-yard. Redistribution of traffic flow has been shown to have a tremendous effect on the directly exposed side, but only a small effect in shielded areas.
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