Question

Explain in your own word the concepts of viscous damping, coulomb damping and stiffness force in a vibration system.

Answer 1

Viscous Damping: Viscous damping is the dissipation of energy that due to the movement of bodies in a fluid medium.

When thick liquids are poured or shifted suddenly, they move slowly due to inertia, which is the resistance to sudden movement. If the same liquid is placed between two plates that are quickly turned in opposite directions, the liquid will resist the turning motion due to its shear force, or the resistance to being pulled apart. Both of these effects can be used in viscous damping equipment, which is used for shock absorbers and vibration control.

Coulomb Damping: The damping force is constant in magnitude but opposite in direction to that of the motion of the vibrating body. It is caused by friction between rubbing surfaces that are either dry or have insufficient lubrication. The friction generated by the relative motion of the two surfaces that press against each other is a source of energy dissipation.

Stiffness Force: Stiffness Force is the force with which an elastic body resists deformation in response to an applied force.