Question

What is principle of virtual work?

(a) work done by external forces is greater than work done by internal forces

(b) work done by external forces is less than work done by internal forces

(c) work done by external forces is equal to work done by internal forces

(d) work done by internal forces is greater than work done by external forces

This question was posed to me in final exam.

The origin of the question is Conditions of Plastic Analysis in division Plastic and Local Buckling Behaviour of Steel of Design of Steel Structures

Answer 1

The correct option is (c) work done by external forces is equal to work done by internal forces

For explanation: The principle of virtual work may be stated as if a system of forces in equilibrium is subjected to virtual displacement, the work done by external forces is equal to work done by internal forces.