FREQUENCY RESPONSE FUNCTIONS FOR STRUCTURAL INTENSITY .1. THEORY

摘要

The frequency response function for structural intensity is a ratio of intensity at a response point to input power at an excitation point. At a zero frequency value, this function represents a ratio of time-averaged intensity at the receiving point to time-averaged power input at the source point, and at all other frequencies the frequency response function represents a ratio of the amplitude of the fluctuating intensity at the receiving point to the amplitude of the fluctuating power at a source point. Thus, the frequency response function for structural intensity reflects both vibration power transfer and fluctuation in a structure, and it allows one to calculate the intensity at a receiving point when the input power at the source point is known. The definition of frequency response function for structural intensity is proposed in this paper. General theoretical formulas and a measurement method are developed to determine frequency response function for structural intensity. A one-degree-of-freedom system, a uniform beam, and plates are analyzed to demonstrate the properties of the frequency response function for use in structural intensity and calculation methods. Some potential uses of this frequency response function for structural intensity are presented. [References: 12]