1

The variation of the magnification factor with the frequency ratio of/o and damping ratio X is shown in Figure 2.133.

When the dynamic force is applied at a frequency much lower than the natural frequency of the system (of/o ^ 1), the response is quasi-static. The response is proportional to the stiffness of the structure, and the displacement amplitude is close to the static deflection.

When the force is applied at a frequency much higher than the natural frequency (of/o ^ 1), the response is proportional to the mass of the structure. The displacement amplitude is less than the static deflection (D< 1).

When the force is applied at a frequency close to the natural frequency, the displacement amplitude increases significantly. The condition at which of/o = 1 is known as resonance.

0 0

Post a comment