| 1. |
- Austrell, Per Erik, et al.
(författare)
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Development of an extremely fatigue-resistant Shock Absorber
- 2014
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Ingår i: Kgk: Kautschuk Gummi Kunststoffe. - 0948-3276. ; 67:11-12, s. 24-31
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Tidskriftsartikel (refereegranskat)abstract
- An extremely fatigue resistant shock absorber was developed from basic mechanics principles using nonlinear elastic material models and finite element analysis. Prototypes were manufactured and tested to confirm the calculations and to find out the fatigue properties. The rubber body fills a cavity at gradually increasing compression. This idea has some clear advantages: A large part of the rubber body is protected against accidental external influences and it is backed up during the deformation by the cavity walls. Also, the stress in the rubber body becomes evenly distributed as only compressive stress is developed in it. The prototypes were tested in nearly 6 million cycles with no visible defects.
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| 2. |
- Coja, Michael, et al.
(författare)
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Rubber versus steel vibration isolators - The audible frequency contest
- 2005
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Ingår i: KGK Kautschuk Gummi Kunststoffe. - 0948-3276. ; 58:11, s. 564-569
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Tidskriftsartikel (refereegranskat)abstract
- The audible frequency axial dynamic stiffness of three vibration isolators plausibly used in the design of a ship main engine suspension system are examined and compared for different static preloads. An indirect measurement method is used to investigate the blocked dynamic transfer stiffness using a specially designed test rig displaying a strong frequency dependence where resonance and antiresonance phenomena appear in the form of troughs and peaks respectively. The significant influence of the preload effects is also assessed for each isolator. Clearly, the rubber isolator presents superior performances in comparison with the two others, steel and combined steel-rubber isolators, over the studied frequency range 200 to 1000 Hz for each preload 30, 40 and 50 kN.
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| 3. |
- Kari, Leif
(författare)
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The non-linear temperature dependent stiffness of precompressed rubber cylinders - An effective shape factor model
- 2002
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Ingår i: KGK-Kautschuk und Gummi Kunststoffe. - 0948-3276. ; 55:3, s. 76-81
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Tidskriftsartikel (refereegranskat)abstract
- A shape factor based non-linear model of a rubber cylinder's temperature and preload dependent static stiffness is presented. The influence of temperature, precompression, material parameters, cylinder length and diameter, are investigated; with the motion split into a homogeneous thermal expansion including a globally equivalent preload deformation. Stiffness depends strongly on preload, particularly in larger shape factors, and on temperature. The model proves superior to traditional work in typical shape factors, with results close to those of finite element models.
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| 4. |
- Lejon, Jonas, et al.
(författare)
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Investigation in the audible Frequency Range of magneto-sensitive Rubber
- 2012
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Ingår i: KGK Kautschuk Gummi Kunststoffe. - 0948-3276. ; 65:10, s. 31-35
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Tidskriftsartikel (refereegranskat)abstract
- An experimental study is conducted where the prestrain dependence of magneto-sensitive rubber in the audible frequency range is studied along with the dependence of the dynamic strain amplitude, frequency and magnetic field strength. The material is natural rubber with a 33% volume particle fraction of irregularly shaped iron metal particles. The results show that with an increase in prestrain up to 1, the magnitude of the dynamic shear modulus decreases. As the prestrain further increases the rate of decrease of the magnitude subsides, indicating that the material is starting to stiffen. Furthermore, an attenuation of the magneto-sensitivity with increased prestrain is noted. As the frequency and magnetic field strengths are increased, the material stiffens. However, it softens with increased dynamic strain amplitude. The results presented here indicate that the pre-strain is an important parameter to consider when describing magneto-sensitive materials.
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| 5. |
- Nepal, Surendra, et al.
(författare)
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A Moving Boundary approach of Capturing diffusants Penetration into Rubber : FEM Approximation and Comparison with laboratory Measurements
- 2021
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Ingår i: KGK Kautschuk, Gummi, Kunststoffe. - : Huethig GmbH & Co. KG. - 0948-3276. ; 74:5, s. 61-69
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Tidskriftsartikel (refereegranskat)abstract
- To model the penetration of diffusants into dense and foamed rubbers a moving -boundary scenario is proposed. After a brief discussion of scaling arguments, we present a finite element approximation of the moving boundary problem. To overcome numerical difficulties due to the a priori unknown motion of the diffusants penetration front, we transform the governing model equations from the physical domain with moving unknown boundary to a fixed fictitious domain. We then solve the transformed equations by the finite element method and explore the robustness of our approximations with respect to relevant model parameters. Finally, we discuss numerical estimations of the expected large -time behavior of the material.
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