| 1. |
- Luks, T., et al.
(författare)
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Contact stress distribution and roll surface temperatures in the roll gap analyzed with different sensors
- 2014
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Ingår i: La Metallurgia Italiana. - : Associazione Italiana di Metallurgia. - 0026-0843. ; 106:1, s. 19-25
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the contact stresses and temperatures during hot and cold rolling have been measured. A work roll containing three different sensors was used for the measurements. There were two contact devices for directly measuring forces and one temperature sensor. One sensor was the "ROLLSURF" sensor. Results obtained with this sensor have been presented earlier [1-3], The measurement principle is based on deformation measurements with strain gauges which were placed on an internal cradle-type roll insert. The second sensor was a friction pin sensor. The forces on the top of the pin were measured by three axis piezoelectric-transducers. The pin sensor was mounted inside the work roll opposite to the ROLLSURF sensor. The third sensor was a thermocouple placed next to the pin sensor. The temperatures were measured very close to the roll surface. The surface boundary conditions including the heat flux and surface temperatures were computed using inverse modelling calculations developed at Brno University of Technology. The main task of this paper is to show a comparison of the contact forces and contact length measured with the strain-gauge sensor and the pin-sensor.
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| 2. |
- Lagergren, J., et al.
(författare)
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A new transducer for local load measurements of friction and roll pressure in cold flat rolling
- 2006
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Ingår i: Steel Research International. - 1611-3683 .- 1869-344X. ; 77:6, s. 430-438
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Tidskriftsartikel (refereegranskat)abstract
- The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, in order to overcome problems in previous measurements In the past 70 years. The new idea Is to increase the contact surface of the transducer, to be larger than the arc of contact. This Is in contrast to the smaller and smaller contact pin design that has been prevailing. The measurements were conducted during cold dry rolling of both copper strips and stainless steel strips In a pilot mill. The recordings were selected from a steady state with no disturbance from the material flow. The transducer was able to simultaneously measure both the normal pressure and the friction stress. An estimation of the coefficient of friction was accordingly performed. The new transducer works very well, it was seen to be robust and able to avoid signal disturbance. The pressure and friction stress distribution results was as expected by the authors and showed good reproducibility, together with a proven agreement between recorded and simulated signals.
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| 3. |
- Presz, W., et al.
(författare)
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Application of surface load - A new calibration method
- 2011
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Ingår i: Proceedings of the 10th International Conference on Technology of Plasticity, ICTP 2011. - 9783514007840 ; , s. 1265-1269
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Konferensbidrag (refereegranskat)abstract
- A special kind of transducer making it possible to measure normal and tangential contact stresses during rolling has been developed. As normal stresses are approximately ten times larger than the tangential, and since cross signals must occur, a proper calibration of the sensor is essential. Calibration must consist of a number of simultaneous applications of known normal and tangential loads. This problem was solved with an especially designed apparatus called Surface Loader (SL). The design makes it possible to apply a force of known value and direction to a small area of the surface. If the value and direction of force is known it might be treated as applying normal and tangential load using the force components. The contact end of the force actuator has a low carbon steel nose, making it possible to reach high friction coefficients. A precise determination of the applied force direction is possible by the invented method of loading. It is applied by a special construction of SL, controlling of the bending moment acting on the actuator by measuring the reaction force and using a special loading procedure: (i) Applying normal force on the sensor surface - a lateral support is used, (ii) Removing the lateral support, (iii) Developing friction by horizontally moving the platform until the moment in the actuator disappears. © 2011 IBF (RWTH Aachen) & IUL (TU Dortmund).
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