Evaluation of Damping

The equation of motion is introduced in Chap. 9 as $$ m\ddot{u}+c\dot{u}+ ku=-m{\ddot{u}}_g, $$ or $$ \ddot{u}+2h{\omega}_0\dot{u}+{\omega}_0^2u=-{\ddot{u}}_g $$ The damping term is recognized as the velocity proportional term in general. There is, however, more damping in the practice, which are listed in the following and will be explained in this chapter