Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
A contact system driven by a high energetic Thomson actuator requires to be decelerated from
full speed down to zero. The forces originated from the interaction between a stationary
copper tube and a moving array of magnets combined with plastic or ferromagnetic material
are used to generate eddy-current damping. Five different configurations of small but strong
(N52) neodymium magnets and spacers were benchmarked for simple free-fall damping. A
comparison between experimental results and simulations (using COMSOL) has shown that
the most effective damping is reached by two consecutive permanent magnets with opposite
magnetization directions ,separated by low-carbon content steel concentrators(SN - Fe
The proposed damper design is the result of the balance between various parameters such as
magnet orientation topology in the array, spacer material and its dimensions, copper tube
thickness and the air gap between copper tube and array.
Furthermore, the design was scaled up and an actuator-drive system was added to perform
more realistic tests, which demonstrated the damping effectiveness on a fast moving armature
actuated by a Thomson coil energized by a capacitor bank. All models in the simulation
predicted the damping effect in advance. Investigations were conducted with two cases: (1) A
solid copper rod was supposed to pass through the magnet array; (2) A plastic shaft was
applied to support the magnet array.
Finally a damping prototype with a plastic shaft was built for completing damping tests. The
results of these tests validated the numerical model with a high degree of accuracy.
2014. , 75 p.