Question

Which of the following statement is correct?

(a) I-section has high torsional stiffness

(b) Closed section has high torsional stiffness

(c) Closed section has less stiffness

(d) Hollow circular tube has more efficiency as flexural member

This question was posed to me in an online interview.

Query is from Factors affecting Lateral Stability in division Design of Beams of Design of Steel Structures

Answer 1

The correct option is (b) Closed section has high torsional stiffness

To elaborate: I-section with the larger in-plane bending stiffness does not have matching stability. in contrast, closed sections such as tubes, boxes and solid shafts have high torsional stiffness, often high as 100 times that of an open section.