According to the principle of superposition of forces, when a Hookean body (An elastic body or material for which Hooke’s law equation can be assumed is said to be Hookean body) is acted upon by some external forces on various points, then the resultant effect on the body is the vector sum of the effects caused by each of the loads acting independently on the respective points of the body.
Superposition principle is equally applicable in measuring the effects in terms of stress, strain, and deflection. However, it is not applicable to materials with non-linear characteristics.