The stiffness in technical mechanics refers to the resistance that a body can offer against elastic deformation due to external influences such as forces or moments.
Stiffness depends on the following factors:
- Geometry of the body
- Material properties (modulus of elasticity, shear modulus)
In general, specific types of stiffness such as tensile, torsional, and bending stiffness can be distinguished. The stiffnesses of a profile, for example, are specified in the cross-sectional values.
The reciprocal of stiffness is compliance.