Two-Channel Laser Vibrometer Techniques for Vibrational Intensity Measurements: Part 2—Longitudinal Intensity

Abstract

This paper extends the application of a two-channel vibrometer technique from the measurement of flexural energy flow (detailed in Part 1) to the measurement of longitudinal energy flow. The two-channel longitudinal energy flow equations and two one-dimensional validation methods are presented along with a discussion of how laser vibrometry functions for the measurement of in-plane vibratory motion. Adaptations of the energy flow equations to laser vibrometry are also presented. Experimental results are illustrated which contain the influence of a bending-induced longitudinal component of motion. Through a mathematical model, the measurement of the longitudinal energy flow is shown to be accurate if the influence of bending-induced longitudinal motion is removed.