Question

St. Venant’s constant is given by

(a) ∑biti^2/3

(b) ∑biti^2

(c) ∑biti^3/3

(d) ∑biti

I had been asked this question in an international level competition.

The question is from Design Strength of Laterally Unsupported Beams in portion Design of Beams of Design of Steel Structures

Answer 1

Correct choice is (c) ∑biti^3/3

The best explanation: St. Venant’s constant is given by It = ∑biti3/3. For open section (e.g. I -section) : It = 2bft3f/3 + bft3w/3.