ABSTRACT
This chapter deals with the simplest system capable of vibratory motion: the single-degree-of-freedom (SDOF) system which, in its discrete-parameters form, is often called harmonic oscillator.
Despite its apparent simplicity, this system contains and exhibits most of the essential features of vibrating systems and its analysis is a necessary prerequisite to any further investigation in vibration theory and practice. In addition, many complex systems behave and can be considered, under certain circumstances, as SDOF systems, thus considerably simplifying the procedures of measurement and analysis. It is often a matter of the modelling scheme that we choose to adopt for the system under examination and of the degree of approximation that we are willing to accept.
