ABSTRACT
Vibration analysis has its beginnings with Galilei (1564-1642), who solved by geometrical means the dependence of the natural frequency of a simple pendulum on the pendulum length (Galilei, 1939). He proceeded to make experimental observations on the vibration behavior of strings and plates, but could not offer any analytical treatment. He was partially anticipated in his observations of strings by his contemporary Mersenne (15881648), a French priest. Mersenne (1635) recognized that the frequency of vibration is inversely proportional to the length of the string and directly proportional to the square root of the cross-sectional area. This line of approach found its culmination in Sauveur (1653-1716), who coined the terminology “nodes” for zero-displacement points on a string vibrating at its natural frequency and also actually calculated an approximate value for the fundamental frequency as a function of the measured sag at its center, similar to the way the natural frequency of a single-degree-offreedom spring-mass system can be calculated from its static deflection (Sauveur, 1701).
