| 1. |
- Bard, Delphine, et al.
(författare)
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Human footsteps induced floor vibration.
- 2008
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Ingår i: The Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 1520-8524 .- 0001-4966. ; 123:5, s. 3356-3356
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Tidskriftsartikel (refereegranskat)abstract
- The generation of the impact sound by the act of the human walk involves two factors, the characters of the footfall and the shape of the induced floor deflection. The footfall noise is created by the impact excitation and the characters of the footfall depend on the foot-ware: the heels and the frequencies of the footfall. The shape of the floor deflection depends rather on the geometrical walking pattern and the construction of the floor structure. In this investigation, the vibration patter of the light-weight construction floor is created by the same walking object, a male with common height. The excitation from the person to the floor in the FE simulations is a function of the length of the foot and the weight of the walking object. The geometrical time history is of the foot step allows it to have different directions in the room. Since the excitation is assumed to be deterministic, differences between the excitation frequencies are estimated from the video records. The goal of this investigation is to determine the difference of the floor structure deflections between two different walking paths: one is perpendicular to the bearing beams and the other is the diagonal path.
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| 2. |
- Davidsson, Peter, et al.
(författare)
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Sound reduction in double walls at low frequencies - A parametric study
- 2003
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Ingår i: Proceedings of the 10th International Congress on Sound and Vibration. ; , s. 4601-4608
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Konferensbidrag (refereegranskat)abstract
- The sound transmission in double walls at low frequencies is studied using a detailed geometric model, based on FEM. The model simulates the experiments carried out to determine the sound reduction index of the wall. The wall properties effect on the sound transmission loss is investigated and also how the sound reduction is affected by the dimensions of the connecting rooms.
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| 3. |
- Flodén, Ola, et al.
(författare)
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The effect of modelling acoustic media in cavities of lightweight buildings on the transmission of structural vibrations
- 2015
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Ingår i: Engineering Structures. - : Elsevier BV. - 1873-7323 .- 0141-0296. ; 83, s. 7-16
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Tidskriftsartikel (refereegranskat)abstract
- Determining the dynamic behaviour of lightweight buildings by means of finite element analyses requires models representing the geometry involved in great detail, resulting in systems having many millions of degrees of freedom. It is, therefore, important to avoid unnecessarily detailed models by carefully considering what is essential to include in the models and the level of details required for describing the phenomena of interest accurately. In the study presented here, it was investigated whether or not air and insulation in cavities of multi-storey wood buildings affect the transmission of low-frequency structural vibrations. It was concluded, by means of numerical studies, that including air and insulation in cavities, modelled as acoustic media, affects the transmission from a floor to the underlying ceiling and surrounding walls. (C) 2014 Elsevier Ltd. All rights reserved.
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| 4. |
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| 6. |
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| 7. |
- Persson, Peter, et al.
(författare)
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Fluid-Structure Interaction Analysis of Vibration Reduction in Pipe Systems
- 2014
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Ingår i: Dynamics of Civil Structures. ; Volume 4, s. 459-468
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Bokkapitel (refereegranskat)abstract
- Transmitted vibrations from water-pipe systems, involving supports standing on a concrete slab and the underlying ground, are investigated here. The effects of varying parameters of the supports, such as location, their elastic modulus and their cross-section, on the level of vibrations transmitted by the water-pipe system are analysed in order to minimise vibrations transmitted to sensitive parts in a facility. A finite element model involving use of both finite and infinite elements was employed for analyses in the frequency domain where account was taken of both fluid-structure interaction and soil-structure interaction. It was concluded from the analyses performed that the parameters of the supports had an appreciable effect on the vibration level in the facility.
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| 8. |
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| 9. |
- Persson, Peter, et al.
(författare)
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Numerical Study of Reduction in Vibrations Induced by Water-Pipe System
- 2015
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Ingår i: Dynamics of Civil Structures. ; 2, s. 407-419
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Bokkapitel (refereegranskat)abstract
- In certain buildings such as synchrotrons and large ground telescopes, strict requirements are stated regarding the vibration levels. Both external and internal vibration sources, for example traffic and indoor water pumps, can have an appreciable effect on the vibration levels in the buildings. The synchrotron research facility MAX IV, which is currently under construction in Sweden, serves as an example case for the analyses. In MAX IV, several water-pipe systems used for cooling purposes will be placed near vibration sensitive equipment. These systems will transmit vibrations, into structural parts of the facility, which could exceed the vibration requirements. Structural modifications of pipe systems are investigated here by means of the finite element method in order to reduce vibration levels in the building. The finite element model employed includes a water-pipe system, adjacent building parts and the underlying soil. The use of fluid-structure interaction is investigated as well as the use of component mode synthesis. This paper focuses on the numerical procedure used as well as the effects on transmitted vibrations by different placements of the pipe supports.
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