Question

What is plastic moment of resistance?

(a) maximum moment in stress strain curve, the point where the curvature can increase indefinitely

(b) maximum moment in stress strain curve, the point where the curvature can decrease indefinitely

(c) minimum moment in stress strain curve, the point where the curvature can increase indefinitely

(d) minimum moment in stress strain curve, the point where the curvature can decrease indefinitely

I had been asked this question in an interview.

This is a very interesting question from Plastic Theory in portion Plastic and Local Buckling Behaviour of Steel of Design of Steel Structures

Answer 1

The correct option is (a) maximum moment in stress strain curve, the point where the curvature can increase indefinitely

To explain: In stress strain curve, the maximum moment is reached at a point where the curvature can increase indefinitely, neglecting the strain hardening benefits. This maximum moment is called plastic moment of resistance and the portion where this moment occurs is called as plastic hinge.