Triangle shape tubing

[RiNaZ]

i need some help guys. There is a guy asking me about using a triangular shape tubing for his FSAE car.

I told him that the benefit from the triangular shape tubing can be obtained from a square tubing and a circle tubing. But he just wanted to know which one is rigid ... and i have explained it to him that it's not about rigidity per se when selecting material for the chasis.

Anybody can offer a better explanation?

RiNaZ

[RiNaZ]

i need some help guys. There is a guy asking me about using a triangular shape tubing for his FSAE car.

I told him that the benefit from the triangular shape tubing can be obtained from a square tubing and a circle tubing. But he just wanted to know which one is rigid ... and i have explained it to him that it's not about rigidity per se when selecting material for the chasis.

Anybody can offer a better explanation?

RiNaZ

[Denny Trimble]

How about explaining to him the concept of moment of inertia in bending? Actually, triangular is the most efficient shape for a column in buckling... a bit of trivia for you there. But otherwise, rectangular is best when you know the direction of bending and align the "tall" dimension with it, and round is best for omnidirectional bending and torsion.

But if you're doing proper spaceframe design, there should be very little bending in your structure. At least, that's a goal to shoot for.

Oh, and I don't know of any triangular tube suppliers. I'm sure it can be done, it's just not very common.

University of Washington Formula SAE ('98, '99, '03, '04)