Principle of superposition:

Explain the principle of superposition.

Sol.: A machine member is subjected to number of forces acting on its outer edges and also at some  intermediate sections along the length of it. The forces are then split up and effects of them are considered on individual sections. The resulting deformation is given by algebraic sum of deformation of individual sections. This is principle of superposition which can be stated as

"The resultant elongation because of several loads acting on body is algebraic sum of elongations caused by individual loads"

Or

"The total elongation in any of the stepped bar because of a load is the algebraic sum of elongations in individual parts of bar".

Mathematically