ABSTRACT
A single degree of freedom (SDOF) system is explained in this chapter. An abstract representation of a SDOF system is shown in Figure 2.1. It consists of a spring (k) and a mass (m) with the assumption that the mass has a SDOF to oscillate in the y-direction only as per the figure. While at rest, the system is said to be in static equilibrium under gravity. However, when the system is disturbed from rest, it oscillates about the static equilibrium position along the y-direction. In dynamics, only the effect of the external disturbance other than gravity on the system is studied. Hence, the dynamic behavior of a structure, in general, remains unaffected due to its orientation in the space. For example, the behavior of a cantilever beam will always be the same, whether its orientation is vertical or horizontal or in an inclined plane. Although a SDOF system is the simplest form of any structure or machine, it is a key element for understanding the dynamics and vibration behavior of even a complex system. Hence, it is important to understand the vibration theory involved in such a simple SDOF system.
