Joist Explore and Report

nominal dimensions 8x2x0.5 t=0.054 straight corner model

cont.

Group 1:Team Lip

Examine the influence of changing the lip length or lip geometry on the elastic buckling (Mcr), and (if time) the DSM strength – share then report

Group 2: Team Flange

Examine the influence of changing the flange width or geometry on the elastic buckling (Mcr), and (if time) the DSM strength – share then report

Group 3: Team Supports

Examine the influence of adding springs or supports at different appropriate locations in the section on the elastic buckling (Mcr) and (if time) the DSM strength – share then report

Group 4: Team Stiffener

Examine the influence of adding folded stiffeners at different appropriate locations in the section on the elastic buckling (Mcr) and (if time) the DSM strength – share then report

Team Exercises

Group 1: Team Lip

• Varied lip length 0.3-2 in., tried return, and 45• Lip length not local buckling, unless really long• Inc. lip length = inc. dist. Buckling• Lip not controlling allowables on this particular

section (800S200-54), even HDS style lip not a big improvement

• Did not try thickening the lip…• Cost analysis….

Group 2: Team Flange

• Tried bigger flange ( 3 in.)..– 12% increase in capacity

• Tried single V in the middle of the 2 in. flange– 17.9% increase in capacity!

• Tried other cases in the flange.. Single V was the winner in these trials

Group 3: Team Supports

• Put springs on top and bottom flanges, distortional goes up 1.21

• Two spring on top flange up to 1.31 (DB)• Springs on web.. Local went way up! (DB?)• Looked at other locations

Group 4: Team Stiffener

• Ribs and V’s in the flange, also looked at stiffening lip, also looked at planking (ribs) in the web

• Double planking in the web, with returns, 18% increase in the moment capacity

• Flange and lip help DB, but needed something in the web to get a big boost…