Applied Mechanics Commons^™

Adhesively Bonded Multi-Material Single Lap Joints Under Static Tensile Loading, Yesim Kokner

Dissertations and Theses

Adhesive joints are widely used in a variety of industrial applications utilizing the improved mechanical properties they provide over traditional mechanical joining methods. [1] The lap joint is a usual test specimen with a view to assessing the strength and properties of joints.

This study deals with the stiffness, strength and fracture behavior of multi-material single-lap joints. It describes the mechanical behavior of a multi-material single lap joints subjected to static tensile loading in the longitudinal direction. First, steel-to-steel and aluminum-to-aluminum joints are tested to establish baseline data. Subsequently, multi-material joints consisting of aluminum-to-steel, aluminum-to-composite, and steel-to-composite joints were tested …

Ternary Flow Simulation Based On The Conservative Phase Field Lattice Boltzmann Method, Chunheng Zhao

Dissertations and Theses

In this thesis, we numerically investigated multi-phase fluid dynamics (2 and 3-phase flow) by solving the Navier-Stokes equations coupled with the conservative phase field (CPF) equations using the Lattice Boltzmann method (LBM). To effectively simulate the large-scale multi-phase physics, we developed an open-source software, IMEXLBM, which can be easily parallelized on both CPUs and GPUs without significant modifications to the code. We first validated various parts of this software and then used this method to study the interaction of rising bubbles with a static oil droplet as well as the engulfment of the water droplet on solids coated with a …

A Micromechanics Study On Ferroelectrics And Multiferroic Composites, Zhiming Hu

Dissertations and Theses

Two kinds of modern composites are studied in this thesis. One is ferroelectric materials, and the other is the multiferroic composites. Based upon the essential properties of these two types materials, several issues need to be considered in order to study their effective properties. For example, the microstructures of the system including the shape, size and the distribution; the phase connectivity; and the loading conditions will impact the results. First, we focus on the investigation of ferroelectrics and its composites. Based on the experimental observations, the nonlinear electromechanical coupling responses of ferroelectrics are strongly depending on the frequency of the …

Wrinkling Of Membrane And Thin Film Under Torsion, Tingting Chen

Dissertations and Theses

Membranes and thin film structures are widely used in modern technologies. Applications include solar sails and sunshields in space missions, biological membranes and flexible circuit boards. Wrinkling of membrane or a stiff film on a soft substrate may occur in either desired or unwanted patterns. This work tries to obtain some understanding on the wrinkling phenomenon and provide guidance in avoiding wrinkling or effectively controlling the wrinkle patterns.

Many works have been published about wrinkling in the thin sheets since the 20^th century. However, there is no simple analytical way to systematically characterize the wrinkling in these studies. In …

The Influence Of Size And Progression Of Intra-Cerebral Hematoma On The Lateral Ventricles, Muhammad J. Ashraf

Dissertations and Theses

Cerebrovascular diseases like intra cerebral hemorrhage are quite deadly and may disturb functioning of the brain, expanding and resulting in formation of an intra cerebral hematoma(ICH). It is imperative to comprehend how hematoma and its expansion inside the brain endangers human life. One of the influences of an ICH inside brain tissue is on the Lateral Ventricles(LV). When the hemorrhage occurs close enough to the lateral ventricles, filled with cerebrospinal fluid(CSF), it disrupts the balance of fluid in LV. A minor pressure change in LV can negatively influence the production of CSF as well as an increase in intracranial pressure. …

Liquid Transmission Line Pulser Circuit For Laser Excitation, Carl Stultz

Dissertations and Theses

The subject of this thesis is the study of liquid dielectric transmission lines and their potential application as an excitation source in high speed, high-repetition rate laser designs. The design problems associated with the construction of high repetition rate (khz), short wavelength lasers have been reviewed and the major shortcomings of conventional electrical driving circuits identified. The identification of these shortcomings and a review of the available literature on electrical circuits for various types of lasers suggested that liquid dielectrics and transmission lines could potentially have significant advantages over more conventional circuitry used in high repetition rate, short wavelength lasers. …

Reduction Of Capacitor Switching Transients By Controlled Closing, John Herman Brunke

Dissertations and Theses

This thesis presents the theory, analysis, testing and implementation of a scheme to reduce shunt compensation capacitor switching transients. The described method is switch the capacitors very near the instant when the bus voltage is at a power frequency zero. This was accomplished with a vacuum breaker on a 230 kV shunt capacitor bank.

The Design And Construction Of A Flashlamp-Pumped Frequency-Doubled Dye Laser Applicable To Long Path Monitoring Of Air Pollutants, Joel Craig Johnson

Dissertations and Theses

The subject of this thesis is the development of a laser light source which could be used in an air pollution monitor to measure the average concentration of sulfur dioxide gas over long paths (>1 km). Many of the problems encountered in designing a long-path pollutant monitor such as instrument cost and reliability, the selection of an optimum spectral region for making the measurement, and light losses due to scattering and turbulence, are considered. The result of these considerations together with a survey of available laser light sources suggested that a frequency-doubled dye laser possessed several advantages over other …

The Development And Testing Of A Fluidic/Pneumatic Position Servo, David Lyle Portin

Dissertations and Theses

This thesis reviews the design and analysis of a fluidic/pneumatic position servo. Rolling diaphragm piston actuators are used for the system drive, and a hydrostatic gas journal bearing is used as the position sensor. The servo has a 1 inch range which is monitored using an electrical capacitive position transducer that was built as an integral part of the system.

Open-loop frequency response testing provides the basis for a mathematical model of the system.

The servo response is linear at frequencies up to 3 Hertz.

The frequency response appeared to be limited by the design of the gas bearing sensor, …

The Analysis Of The Deflection And Containment Of A Hot Plume By Side Draft Exhaust Hooding, Douglas H. Macgowan

Dissertations and Theses

A common industrial ventilation and pollution problem results when a thermally buoyant polluted plume of air must be exhausted away from a work area to allow achievement of air pollution standards. Generally, a close fitting canopy hood is one of the most effective means of exhaust containment; however, physical restrictions or the operation itself often prevent such an arrangement, and a hood located to the side of the operation is required. This arrangement requires the exhaust to bend and contain the vertically rising plume with a horizontal sweep of exhaust air across the surface of the operation.

A review of …