Stiffness of a structural member« Back to Questions List

Stiffness of a structural member is defined as its resistance to deformation. It can be axial stiffness, flexural stiffness or torsional stiffness.
Axial stiffness can be defined as given below;
Consider a rod of area A , length L and applied with axial load P.
It’s change in length (delta L) = P (L /AE) or P/(AE/L)
The term AE/L is the resistance to axial deformation and controls the deformation. If AE/L is more axial deformation is less. So we can say that axial stiffness of a rod is AE/L

Stiffness method of structural analysis is very useful and widely used for solving indeterminate structures.