Eddy Current Brake Behavior (Accelerating From Rest)

[SCM25]

Hey guys,

So I'm interested in the application of an eddy current brake system as a high intensity shock absorber of some sort. The system would consist of permanent magnets concentrated on a stationary, non ferromagnetic metal. If a sudden, intense force were to act upon the non ferromagnetic metal, how effective would the magnets be at slowing it down and stopping it? Would it be stopped almost immediately? As stated above, the force would be sudden and violent, so the metal would want to accelerate quickly. I know that there are many factors that will effect the outcome (magnet strength, metal thickness, etc.) and calculating the retarding force of an eddy current brake at high speeds is a difficult task, but in general what kind of behavior should I expect? Any and all input would be much appreciated. Thank you.

 

[Gordianus]

Very few cases can be worked out analytically. I´d suggest Smythe´s "Static and Dynamic Electricity"; he studies a rotating disk in a uniform magnetic field and computes the resulting torque. For more complex systems a numerical package is almost mandatory. As a general rule, the higher the field's strength and the metal's conductivity, the higher the braking force..

 

[lychette]

electromagnetic brakes are a common way to brake fairground rides. A magnet on the car runs in an aluminium or copper tube at the end of the ride.
You might find some practical examples in this area.

 

[berkeman]

Hey guys,

So I'm interested in the application of an eddy current brake system as a high intensity shock absorber of some sort. The system would consist of permanent magnets concentrated on a stationary, non ferromagnetic metal. If a sudden, intense force were to act upon the non ferromagnetic metal, how effective would the magnets be at slowing it down and stopping it? Would it be stopped almost immediately? As stated above, the force would be sudden and violent, so the metal would want to accelerate quickly. I know that there are many factors that will effect the outcome (magnet strength, metal thickness, etc.) and calculating the retarding force of an eddy current brake at high speeds is a difficult task, but in general what kind of behavior should I expect? Any and all input would be much appreciated. Thank you.

The braking force is proportional to the velocity (or some power of it), so as the object slows down, the braking force decreases. You would probably need some other augmentation to fully stop your object.