Strengthening Sheetmetal

[TheReg]

I am using 26ga. sheetmetal (9-3/4 wide) with two tabs welded (for self tapping screws), however, the the srews are torqued the sheetmetal bends. Will placing a groove across the width of the metal (over the top of this section) provide enough strength to overcome the screw torque? Can anyone provide me with some suggestions and/or forumlas to determine this?

 

[fcsuper]

Have you considered gussetting, bent or welded ribs across the width?

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

 

[TheReg]

I have considered ribs (which I probably classified wrong, as grooves). Is there calculations which will help me determine how many ribs (grooves) are needed and how much doing so will strengthen the sheet metal.
Gussets, unfortunately, are not an option due to space limitations.

 

[ajack1]

Any form in the sheet metal will make it stronger, as well as ribs consider dimples in the local area. Also instead of welding brackets have you considered plunging holes for the self tapping screws or even piercing a helix, I believe Dayton punch and die do these as an off the shelf option.

Sorry I have no idea about formulas for this.

 

[RossABQ]

You can analyze the effect of a rolled rib from its shape. Figure the moment of inertia of the shape of the rib, and look at bending from some postulated force. In other words, think of the rib as a structural member independent of the rest of the sheet. This is somewhat simplistic but good enough.

 

[NickE]

You are not talking strength here (not directly) you are talking about stiffness.

 

[TheReg]

NickE, your correct...my verbage takes another hit

 

[alejandroillini]

well they make pems for as thin a 24 ga then you could form the tabs instead of welding and since you will not be cutting threads into the metal then you don't need to worry about the torque twisting the metal. I don't know if you are from a sheet metal shop or designing something out of sheet metal if you need someone to manufacture your sheet metal parts try

http://www.accuratemetalfab.com

I hope that helps
ps I am guessing the reason you are welding tabs instead of forming is because you will get no threads in 26 gage.