Conveyor Bent Vibration

[bootlegend]

I have a conveyor support on a structure that supports a vibrating screen. See attachment. There is a vibration damping pad between the support baseplate and the main structure. I'm still seeing a some vibration in the longitudinal direction. I know it isn't ideal, but would bolting (welding is a last resort) an additional Wx18 flange to flange be an acceptable method of stiffening the column. I've done some natural frequency comparisons and adding plates to the flanges alone don't provide enough stiffness.

 

[MotorCity]

I don't think scabbing on a member will help. It looks like the end of the existing bent is pinned, so any member you add to it will just go along for the ride.

I'd say your best bet is to add a diagonal brace normal to the bent.

 

[charliealphabravo]

If the longitudinal movement is the result of deflection of the bent then sistering with an identical member will address that. As you show it you will double the weak axis stiffness of the bent.

If you turn the new 8x18 90 degrees then you should have something more like 5 times the stiffness since Sx is something like four times Sy for the 8x18. With a 5" flange and 8" depth you should have just enough room to reach the back side with a tool if the web of the new bent is bolted to the flange of the old bent.