Equivalent brace for plate

[mrMikee]

About a year ago I found a website that had a formula for sizing an x-brace that would be equivalent to a plate for in-plane forces. I can't find where I filed this and can't locate it on the web again. Since my structural analysis software (Multiframe) doesn't have a plate element this information would be useful for modeling bins etc. I think it was found on a site with structural engineering formulas that's been mentioned in this forum.

Does this sound familiar to anyone?

Thanks,
-Mike