For stable structures, one of the important properties of flexibility and stiffness matrices is that the elements on the main diagonal (i) Of a stiffness matrix must be positive (ii) Of a stiffness matrix must be negative (iii) Of a flexibility matrix must be positive (iv) Of a flexibility matrix must be negativeThe correct answer is

Structural analysis is the process of calculating and determining the effects of loads and internal forces on a structure, building or object. It is also a branch of solid mechanics which uses simplified models for solids like bars, beams and shells for engineering decision making.