Structural Configuration Study For An Acoustic Wave Sensor

Structural Configuration Study for an Acoustic Wave Sensor

Acoustic sensors have been developed for many years. However, most acoustic sensors in application are chemical sensors which rely on the chemical material principle to predict mechanical vibration response signals subject to acoustics waves. In this book, we propose the new acoustic wave detection approach, considering that a continuous structure such as beam or plate with several response characteristics from an acoustic excitation can be a candidate for a sensor used to locate an acoustic source. Acoustic waves will be successfully reconstructed only if this inverse method provides bounds to the ill-conditioned results during the identification process. So the Tikhonov regularization technique is employed for the wave reconstruction work from responses. Effects of sensor design parameters, such as material properties, sensor structure dimensions and random noise background on the wave detection quality have been evaluated. Results show that such an approach is very good and reliable, it can be practical in acoustic sensing and will have wide applications in the field of acoustic wave sensing, especially, in the areas of security and disaster recovery by using qualified sensors

Structural Configuration Study for an Acoustic Wave Sensor

A continuous structure has several response characteristics that make it a candidate for a sensor used to locate an acoustic source. Primary goals in developing such a sensor structure are to ensure that the response is rich enough to provide information about the impinging acoustic wave and to detect the direction of travel without being too sensitive to background noise. As such, there are several factors that must be examined with regard to sensor configuration and measurement requirements. This dissertation describes a set of studies that examine various configuration requirements for such a sensor. Some of the parameters of interest include the size, or aperture of the structure, boundary conditions, material properties, and thickness. The response of the structure to transient sinusoidal wave excitations will be examined analytically. The time-domain response of an Euler-Bernoulli beam excited by a traveling sinusoidal excitation is obtained based on modal superposition and verified by using a finite element method. Then, an approach using simple basis functions will be applied to achieve the goal of more efficient response and force identification. The moving force is identified in the time domain by extending previous inverse approaches. The Tikhonov regularization technique provides bounds to the ill-conditioned results in the identification problem. Both simulated displacement and velocity are considered for use in the inverse. To evaluate the method and examine various configurations, simulations with different numbers of sinusoidal half-cycles exciting the sensor structure are studied. Various levels of random noise are also added to the simulated displacements and velocities responses in order to study the effect of noise in moving wave load identification. Such a new approach in acoustic sensing has applications in the areas of security and disaster recovery.

Physical Model Study of Wave Diffraction-refraction at an Idealized Inlet