| 1. |
- Claesson, Åsa, et al.
(författare)
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lntegrated Optical Fiber Sensors in Additive Manufactured Metal Components for Smart Manufacturing Applications
- 2019
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Ingår i: Smart Systems Integration; 13th International Conference and Exhibition on Integration Issues of Miniaturized Systems.
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Konferensbidrag (refereegranskat)abstract
- This work combines fiber optic sensors with additive manufacturing to enable integration of temperature and strain sensors in metal components. In this paper, we present a fiber optic sensor network integrated in press hardening tools to monitor the contact between the tool and the metal sheet during forming operation. The tools are manufactured through metal powder bed fusion using laser melting processes (PBF-SLM), after which the tools are prepared for sensor integration. A demonstrator press hardening tool with integrated fiber optic sensors was heated using an electric heat foil and the sensor measurements was compared to a thermal simulation model. The sensor technology is based on Fiber Bragg Gratings (FBGs), integrated at several positions along the optical fiber. FBGs are in-fiber sensors that are multiplexed. lt is possible to place hundreds of FBG sensors along one single fiber, thus allowing for quasidistributed sensing of temperature or strain. The optical fiber itself can be less than 100 micrometer in diameter, allowing for sensing at several points in a minimally invasive way, when integrated in a tool or component.
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| 2. |
- Lejon, Jonas, et al.
(författare)
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A constitutive model of the dynamic shear modulus dependence on temperature, prestrain, dynamic strain amplitude and magnetic field for magneto-sensitive elastomer
- 2021
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Ingår i: International Journal of Solids and Structures. - : Elsevier BV. - 0020-7683 .- 1879-2146. ; 219, s. 106-119
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Tidskriftsartikel (refereegranskat)abstract
- A constitutive model for the temperature, prestrain, dynamic strain amplitude and the magnetic field dependence of the dynamic shear modulus for a magneto-sensitive (MS) elastomer is developed. It is an augmentation of a model consisting of an elastic, fractional order derivative viscoelastic and a nonlinear amplitude-dependent smooth Coulomb friction model. The magnetic field dependence is reflected by a parabolic function with an upper limit. A Yeoh formulation of the strain energy function is applied to represent the prestrain dependence. To cover the temperature dependence, a Williams-Landel-Ferry function and an Arrhenius function are used. After parameter identification, a good agreement between the simulation and measurement results is shown, which demonstrates the ability of the model to cover the prestrain and temperature dependency of MS elastomer. Therefore, the expansion of the model to cover the prestrain and temperature enables the prediction of the mechanical performance of MS elastomer under various conditions and improves the possibilities for MS dampers and mounts to meet design criteria.
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| 3. |
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| 5. |
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| 6. |
- 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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| 7. |
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| 8. |
- Lejon, Jonas, et al.
(författare)
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Measurements on the Temperature, Dynamic Strain Amplitude and Magnetic Field Strength Dependence of the Dynamic Shear Modulus of Magnetosensitive Elastomers in a Wide Frequency Range
- 2013
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Ingår i: Journal of Vibration and Acoustics-Transactions of the ASME. - : ASME International. - 1048-9002 .- 1528-8927. ; 135:6, s. 064506-
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Tidskriftsartikel (refereegranskat)abstract
- A measurement study is conducted to investigate how changes in temperature, dynamic strain amplitude, and magnetic field strength influence the behavior of a magnetosensitive material. During the measurements seven temperatures, four magnetic fields, and three dynamic strain amplitudes are used over a 200 to 800 Hz frequency range. The results indicate a decrease in shear modulus magnitude as the dynamic strain amplitude is increased. As the frequency and magnetic field strength increases the magnitude increases. However, the measurements indicate that the temperature is the most influential of the parameters as the material stiffens significantly when the temperature reaches the transition phase. Understanding the temperature dependence increases the knowledge of magnetosensitive materials.
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| 9. |
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| 10. |
- Lejon, Jonas, et al.
(författare)
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Preload, frequency, vibrational amplitude and magnetic field strength dependence of magnetosensitive rubber
- 2009
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Ingår i: Plastics, rubber and composites. - : Informa UK Limited. - 1465-8011 .- 1743-2898. ; 38:8, s. 321-326
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Tidskriftsartikel (refereegranskat)abstract
- The preload dependence of magnetosensitive rubber is experimentally studied along with the influence of frequency, vibrational amplitude and magnetic field strength. The material studied is an iron particle filled natural rubber with a volume particle fraction of 33%, which is close to the optimal particle concentration. The results of the measurements show that an increased preload decreases the influence of magnetic field strength and they also suggest that an increase in the magnetic field reduces the influence of the preload. Measurements of the magnitude of the dynamic shear modulus also display a preload dependence. These results imply that in a description of these materials, the preload should be taken into account, especially since magnetosensitive elastomers are used in applications where they are often exposed to preloads.
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