Variability of vibration input power to a beam structure

Structure-borne source which transmits vibration power to the supporting structure especially in buildings plays a major role in contributing the noise pollution and this remains a challenging problem for noise treatment. In practice however, the lack of knowledge of phase of the excitation force from the structure-borne source creates variability in the input power. This paper discusses the quantification of the frequency-averaged mean and variance from the variability in the input power for the case of two excitation point forces to a beam structure. It is found that quantification of the frequency-average variability from a finite beam structure can be approached by using that from the corresponding infinite beam structure. 1 2 1   j j e F e F F 