Tubular frame vs Hibrid/Tubular with composite sandwich panels

[Tudor Miron]

Hi All,
I know there where many threads on this subject but I never saw any comparative information. As far as I understood teams who switched from pure tubular to tubular frame with panels instead of triangulation did this in search for less weight with same stiffness or vise versa. Would anybody share comparision information for stiffness etc.?
Also if someone will share more detailed information on the way they attached the panels to tubes? I know it was addressed before but my English doesn't help so this is way I ask for DETAILED http://fsae.com/groupee_common/emoticons/icon_smile.gif explanation.

Thank you
Ted

[Tudor Miron]

Hi All,
I know there where many threads on this subject but I never saw any comparative information. As far as I understood teams who switched from pure tubular to tubular frame with panels instead of triangulation did this in search for less weight with same stiffness or vise versa. Would anybody share comparision information for stiffness etc.?
Also if someone will share more detailed information on the way they attached the panels to tubes? I know it was addressed before but my English doesn't help so this is way I ask for DETAILED http://fsae.com/groupee_common/emoticons/icon_smile.gif explanation.

Thank you
Ted

[Nate Notta]

I'm interested in this as well, for our 2006 team. Photos would be appreciated.

[Daves]

We are using carbon fiber supported by structural foam. Check out the following webpage to see how:

http://www.letu.edu/_Academics/Engineering/engineering/student-projects/formula/teamchassis.html

[Tudor Miron]

Thank you Dave,
What foam did you use? Rohacell? Anything also? While your animation is beautiful but this doesn't help much in terms of details http://fsae.com/groupee_common/emoticons/icon_smile.gif
Also how about comparision stifness numbers - tubular vs. hibrid?
Sory for being such a PITA http://fsae.com/groupee_common/emoticons/icon_wink.gif

Thank you
Ted

[Ben Beacock]

We just finished a physical bending test of a hybrid panel. 0.4mm Al skin, 5/8" Al honeycomb, 5/8"x.049 tubing with a diagonal member as well.
Yield and ultimate strength were almost identical to the safety equivalent in bending. Its not as stiff in bending, but that is likely due to the very thin skin(we will go a bit thicker).