Do you start with an frame like so
http://www.solidworks.com/sw/educati...4_ENU_HTML.htm
and then you are looking to place a sheetmetal floor to mount other subsystmes to?
Or are you looking for your frame to be sheetmetal?
Sheet metal can be use structurally - but you have to know how much weight will be distributed.
My intern, Ian, created a great sheet metal model of a joist
http://blogs.solidworks.com/teacher/...st-hanger.html
You can download the file and take a look at how the part was constructed.
Right-click the gray area of the SolidWorks Main menu to bring up the Sheet Metal toolbar. You have to use Sheet Metal features - not Solid features. Give me some ideas in your design direction. Marie