Identifier

etd-05192010-064633

Degree

Master of Science in Mechanical Engineering (MSME)

Department

Mechanical Engineering

Document Type

Thesis

Abstract

Piezoelectric materials have the ability to provide desired transformation from mechanical to electrical energy and vice versa. When a mechanical force is applied to the piezoelectric material an electrical voltage is generated and when an electrical voltage is applied to the piezoelectric material it gets strained or deformed. Owing to these characteristics piezoelectric materials can be used as a sensor, an actuator, as well as a power generation unit. The high brittleness property of the original piezoelectric material is one of the major constraints in using them in the engineering applications. In order to overcome this disadvantage the composite piezoelectric materials were developed. The piezoelectric fiber composite product is flexible and can sustain the extensive deformation without being damaged, and is compatible with the composite structures’ processing procedure; which makes it, an ideal material to be used as an embedded sensor & a force actuator within the composite structures. The smart joint can be designed to have the piezoelectric materials embedded in them, the piezoelectric materials can detect the various loads that act on the composite joint and could provide the required counter-balancing force to the excitation forces acting on the joint; and thereby could reduce or even eliminate the effects of stress concentrations at the composite joint. A high stress concentration is one of the principal causes of structural failures. In this work our main objectives are to study the sensing and force generation capabilities of various commercially available composite piezoelectric configurations through series of experimentations and to compare their performances in order to use them in the smart joint applications. Firstly, the sensing capabilities of these products were investigated at various input frequencies and amplitudes of the dynamic loads. Secondly, the tensile and bending force generation capabilities of these products were inspected with respect to various input excitation voltages. The results of these experiments depict that the voltage signals generated from these products are proportional to amplitudes of mechanical movement, with good response at high frequency, even at micrometer deformation domain; but the force generation is relatively low under the current input conditions and configuration under study.

Date

2010

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Wahab, M. A.

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