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Mechanical Engineering Commons™

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2002

Theses/Dissertations

The University of Maine

Articles 1 - 8 of 8

Full-Text Articles in Mechanical Engineering

Mechanical Testing Of Epoxy Adhesives For Naval Applications, Michael James Boone Jan 2002

Mechanical Testing Of Epoxy Adhesives For Naval Applications, Michael James Boone

Electronic Theses and Dissertations

With advances in composite technology and an understanding of composite application, requirements to develop new design approaches exist. With composite structures today, a basic understanding that both material architecture and joining process, affect the strength of the structure. These design requirements force old techniques of joining, such as bolting and riveting to be re-evaluated. Advantages of adhesives over mechanical means of fastening include higher stiffnesses, more uniform load distribution, parts consolidation, no holes drilled in adherends (with resulting stress concentrations), and, generally, less labor. Adhesives have proven to be a good solution for joining when composites are utilized, but this …

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Optimal Recovery Of Elastic Properties For Anisotropic Materials Through Ultrasonic Measurements, Miao Sun Jan 2002

Optimal Recovery Of Elastic Properties For Anisotropic Materials Through Ultrasonic Measurements, Miao Sun

Electronic Theses and Dissertations

Full knowledge of material elastic properties is required to facilitate design in many applications. The existence of misorientation between the geometric axes of the part and the material symmetry axes has in particularly created challenged in design of composite structure. In this thesis the potential for optimal identification of material symmetries for a general anisotropic material through a water immersion technique is explored. The concept is extensible to any class of symmetry groups and does not assume a-priori knowledge of the material. Initial experimental results for determining the elastic constants as well as locating the symmetry planes are presented. Many …

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Stress Analysis Of Tapered Sandwich Panels With Isotropic Or Laminated Composite Facings, Huyue Zhao Jan 2002

Stress Analysis Of Tapered Sandwich Panels With Isotropic Or Laminated Composite Facings, Huyue Zhao

Electronic Theses and Dissertations

Structural sandwich construction is used in many air and space vehicles, cargo containers, boats and ships. Connection of the sandwich construction component to a framework or substructure is a critical issue in the detail design for sandwich construction. The tapered connection where the facings are drawn together at the support is one of the most efficient types of connections in composite sandwich construction. We present a tapered sandwich theory that is simple to use, yet accurately predicts the stresses and deflection of both symmetric and non-symmetric tapered sections. In this investigation we assume that the facings are relatively thin and …

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High Temperature Compression Testing Of An Advanced Carbon-Carbon Composite In An Oxidizing Atmosphere, Joshua C. Walls Jan 2002

High Temperature Compression Testing Of An Advanced Carbon-Carbon Composite In An Oxidizing Atmosphere, Joshua C. Walls

Electronic Theses and Dissertations

Compression testing of an advanced, three-dimensional weave, carbon-carbon composite was performed from room temperature to 2192°F (1200°C) in an oxidizing environment. The material tested is primarily used for missile nose cones and rocket nozzles. A test system and test method was developed for performing high temperature compression testing and techniques were developed for machining the material to minimize fiber damage and maintain accurate tolerances. Test specimens were cut from a block of the test material in the three principal fiber orientations, and off-axis tests were cut at 45" orientations to each principal fiber direction. The specimens were tested by direct …

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Evaluation Of Dynamic Properties Of A Carbon-Carbon Composite At Elevated Temperatures., Sean Patrick Bunker Jan 2002

Evaluation Of Dynamic Properties Of A Carbon-Carbon Composite At Elevated Temperatures., Sean Patrick Bunker

Electronic Theses and Dissertations

Methods for in-situ monitoring of high temperature composite materials are important in a number of technological applications. In this work a method is developed that makes use of solid cylindrical waveguides to monitor the change of elastic properties and the oxidation reaction of carbon-carbon composites with change in temperature. The apparatus is designed to allow ultrasonic measurements to be performed in a controlled atmosphere at temperatures up to llOO°C. Signal processing required to obtain quantitative information is considered for the experimental apparatus described.

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Los Angeles-Long Beach Harbor Pier 400 Harbor Resonance Study Using Numerical Model, Cgwave, Dongcheng Li Jan 2002

Los Angeles-Long Beach Harbor Pier 400 Harbor Resonance Study Using Numerical Model, Cgwave, Dongcheng Li

Electronic Theses and Dissertations

Ports and harbors can be used for commercial, recreational and military purpose. Compared to other kinds of transportation (railroad, airplane, highways), waterborne commerce has two significant advantages: low cost and high capacity. Many nations use waterborne commerce as a major source of transport. Several major U.S. portsharbors currently have renovation plans in response to the future expansion of ocean-borne world commerce, and coastal engineering projects generally require a detailed knowledge of the wave field in the project areas. Physical and numerical model studies are often conducted concurrently for these projects to evaluate technical feasibility and to optimize design alternatives. A …

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Numerical Model Of The Transient Effects Of A Heat Of Fusion Reservoir Interacting With Two-Phase Flow, Anne-Marie Bechard Thibodeau Jan 2002

Numerical Model Of The Transient Effects Of A Heat Of Fusion Reservoir Interacting With Two-Phase Flow, Anne-Marie Bechard Thibodeau

Electronic Theses and Dissertations

The object of this thesis is to develop a numerical model that simulates the transient behavior of a coaxial, thermal energy storage system consisting of a phase changing material ( P O interacting with a two-phase fluid. The purpose of this model would be to have a useful design tool that could be applied when sizing and building iceon- coil, cooling systems (ice-banks). The numerical model is an explicit finite volume approximation applied to the enthalpy method. It solves a two-dimensional, axisymrnetric, heat conduction problem with conjugate forced convection at its inner boundary. Natural convection is neglected in the PCM. …

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Dynamic Response Of A Mobile Offshore Base Hydroelastic Test Model, Vijay Venkataraman Jan 2002

Dynamic Response Of A Mobile Offshore Base Hydroelastic Test Model, Vijay Venkataraman

Electronic Theses and Dissertations

The objective of the work presented in this thesis deals with the study of dynamic response of a Mobile Offshore Base (MOB) hydroelastic test model. The MOB is a very large floating structure consisting of multiple self-propelled, semi-submersible modules. Physical scale model testing of a notional MOB concept has been conducted and the experimental results have been provided for one, two and four module configurations. This thesis focuses on utilizing the experimental data to understand the dynamic response of the MOB hydroelastic scale module. The analysis of the data is conducted using popular linear and nonlinear data processing techniques. The …

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