Wayne,

 

I understand that you were requesting the origin of the 125 lb clamp preload.  I am attaching a presentation from last year detailing the iterations of clamp design and preload (slide 5 with the table is key).  The clamp design has changed since then from a 3 piece assembly to a one piece u-shaped bracket so the stress loading would not as accurate as the presentation I did last week (let me know if you need that file).   The summary statements still hold.  They are:

 

§         Iterations show that Belleville washers  should be designed with a stiffness of 5,000 - 10,000 lb/in and a preload of 100 – 125 lbs.  This corresponds to case 2 and case 6.

§         Clamp Stresses depends mostly on preload.

§         Using no clamps, results in larger displacements and gaps, but this effect is less for the stiff winding pack.

 

If you have any questions please feel free to call me.

 

All the best

 

Kevin

 

 

 

Kevin Freudenberg

Fusion Energy Division

Oak Ridge National Lab.

Oak Ridge, TN 37831-6169

Building 5700 Room B304

865 574-1310