Amplificador de señal analógico basado en conceptos biomiméticos. Desarrollo de modelos computacionales y validación experimental

Abstract

This Thesis studies the characteristics of an acoustic transducer bioinspired by the structure of the lower maxilla of an odontoceto. In this case a Cuvier's beaked whale (Ziphius cavirostris). The transducer working mechanism is based in a coupled system, with components identified in the maxilla.To analyze the transducer a simplified 2D model composed by a horn shaped closed cavity is modeled. The cavity is coupled with a flat belt. The belt has one part inside the cavity and the other part outside of it. The belt traverses the cavity wall and it is in charge to pick the vibrations from outside and introduce it inside the cavity. The transmission is obtained through the belt bending. A sustained external load with the right frequency contents will allow the system to reach a stationary pressure intensity distribution inside the cavity. Frequencies with modal shapes that show an important intensity increase at the horn tip are of special interest because of the signal amplification. A finite element model is constructed to study the transducer coupled modes and a prototype is constructed to validate the numerical results.A numerical methodology to construct and validate a tetrahedral finite element for isotropic porous materials is presented. The methodology allows constructing linear and 2D elements. It is extended to model orthotropic porous materials behavior.At the end, one of the horn walls is made of an orthotropic material and the external belt is glued to it in order to configure a belt over an elastic foundation. Modal response is evaluated and the porous material effects in the transducer efficiency and further improvements are discussed. vi B.3.1. ESQUEMA DEL ALGORITMO DE LA INTEGRAL DE DUHAMEL B.4. REFERENCIAS C. CARACATERIZACIÓN EXPERIMENTAL DEL EXCITADOR ELECTRODINÁMICO