Estimating acoustic radiation from a Bernoulli–Euler beam using shaped polyvinylidene flouride film

This paper examines numerically the use of arrayed shaped polyvinylidene fluoride film sensors to obtain an estimate of the far-field radiated power from a clamped-clamped Bernoulli–Euler beam excited by a sinusoidal point force. Distributed sensors are designed that are sensitive to the radiated power. Fourier analysis of point and distributed sensor outputs is used to estimate the beam’s radiated power. The numerical results of the estimated power obtained from the point and distributed sensors are compared to those predicted by the theoretical model and the performance of the two sensor types is assessed. The results show that the shaped sensors provide a reasonable estimate of the strain transforms over the region of interest, when compared to the exact theoretical predictions, for the first five beam resonance frequencies and for frequencies located approximately midway between resonance frequencies. The distributed sensors also give consistently better predictions of the strain transforms for all frequencies considered when compared to the point sensor results. The power predictions using shaped sensors range from 21 to 3 dB relative to the exact theoretical results for most of the frequencies analyzed. This contrasts to the 36–68 dB range of relative power estimates using point sensors. © 1997 Acoustical Society of America. @S0001-4966~97!02606-4#