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Mechanical Engineering Commons

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Missouri University of Science and Technology

2014

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Articles 1 - 29 of 29

Full-Text Articles in Mechanical Engineering

Modeling Of Thermal And Mechanical Behavior Of Zrb₂-Sic Ceramic After High Temperature Oxidation, Jun Wei, Lokeswarappa R. Dharani, K. Chandrashekhara, Greg Hilmas, William Fahrenholtz Nov 2014

Modeling Of Thermal And Mechanical Behavior Of Zrb₂-Sic Ceramic After High Temperature Oxidation, Jun Wei, Lokeswarappa R. Dharani, K. Chandrashekhara, Greg Hilmas, William Fahrenholtz

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Fano Resonances Realized In Thz Metamaterials Composed Of Continuous Metallic Wires And Split Ring Resonators, Z. Li, S. Cakmakyapan, B. Butun, C. Daskalaki, S. Tzortzakis, Xiaodong Yang, E. Ozbay Nov 2014

Fano Resonances Realized In Thz Metamaterials Composed Of Continuous Metallic Wires And Split Ring Resonators, Z. Li, S. Cakmakyapan, B. Butun, C. Daskalaki, S. Tzortzakis, Xiaodong Yang, E. Ozbay

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Stress Amplification During Development Of The Tendon-To-Bone Attachment, Y. Liu, A. G. Schwartz, Victor Birman, S. Thomopoulos, G. M. Genin Oct 2014

Stress Amplification During Development Of The Tendon-To-Bone Attachment, Y. Liu, A. G. Schwartz, Victor Birman, S. Thomopoulos, G. M. Genin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


The Effects Of Electrode Size And Configuration On Plasma Actuator Thrust And Effectiveness At Low Pressure, Paul Daniel Friz, Joshua L. Rovey Sep 2014

The Effects Of Electrode Size And Configuration On Plasma Actuator Thrust And Effectiveness At Low Pressure, Paul Daniel Friz, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Experimental Characterization Of Optical Nonlocalities In Metal-Dielectric Multilayer Metamaterials, L. Sun, F. Cheng, C. J. Mathai, S. Gangopadhyay, Jie Gao, Xiaodong Yang Sep 2014

Experimental Characterization Of Optical Nonlocalities In Metal-Dielectric Multilayer Metamaterials, L. Sun, F. Cheng, C. J. Mathai, S. Gangopadhyay, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Effects Of Local Ph On The Formation And Regulation Of Cristae Morphologies, Dong Hoon Song, Jonghyun Park, Martin A. Philbert, Ann Marie Sastry, Wei Lu Aug 2014

Effects Of Local Ph On The Formation And Regulation Of Cristae Morphologies, Dong Hoon Song, Jonghyun Park, Martin A. Philbert, Ann Marie Sastry, Wei Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Cristae, folded subcompartments of the inner mitochondrial membrane (IMM), have complex and dynamic morphologies. Since cristae are the major site of adenosine triphosphate synthesis, morphological changes of cristae have been studied in relation to functional states of mitochondria. In this sense, investigating the functional and structural significance of cristae may be critical for understanding progressive mitochondrial dysfunction. However, the detailed mechanisms of the formation and regulation of these cristae structures have not been fully elucidated. Among the hypotheses concerning the regulation of cristae morphologies, we exclusively investigate the effects of the local pH gradient on the cristae morphologies by using ...


Integration Of Microwave And Thermographic Ndt Methods For Corrosion Detection, Dustin F. Pieper, Kristen M. Donnell, Mohammad Tayeb Ahmad Ghasr, Edward C. Kinzel Jul 2014

Integration Of Microwave And Thermographic Ndt Methods For Corrosion Detection, Dustin F. Pieper, Kristen M. Donnell, Mohammad Tayeb Ahmad Ghasr, Edward C. Kinzel

Electrical and Computer Engineering Faculty Research & Creative Works

Infrastructure health monitoring is an important issue in the transportation industry. For the case of cement-based structures in particular, detection of corrosion on reinforcing steel bars (rebar) is an ongoing problem for aging infrastructure. There have been a number of techniques that have shown promise in this area including microwave nondestructive testing (NDT) and thermography. Thermography is quite advantageous as it is an established method, and can be utilized for large inspection areas with intuitive results. Typical heat sources include induction heating and flash lamps, but these are not without drawbacks. Microwave nondestructive testing has also been successful at detecting ...


An Investigation Of The Effect Of Direct Metal Deposition Parameters On The Characteristics Of The Deposited Layers, Tarak A. Amine, Joseph William Newkirk, Frank W. Liou Jul 2014

An Investigation Of The Effect Of Direct Metal Deposition Parameters On The Characteristics Of The Deposited Layers, Tarak A. Amine, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

Multilayer direct laser deposition (DLD) is a fabrication process through which parts are fabricated by creating a molten pool into which metal powder is injected as particles. During fabrication, complex thermal activity occurs in different regions of the build; for example, newly deposited layers will reheat previously deposited layers. The objective of this study was to provide insight into the thermal activity that occurs during the DLD process. This work focused on the effect of the laser parameters of newly deposited layers on the microstructure and mechanical properties of the previously deposited layers in order to characterize these effects to ...


Bi-Harmonic Cantilever Design For Improved Measurement Sensitivity In Tapping-Mode Atomic Force Microscopy, M. Loganathan, Douglas A. Bristow Apr 2014

Bi-Harmonic Cantilever Design For Improved Measurement Sensitivity In Tapping-Mode Atomic Force Microscopy, M. Loganathan, Douglas A. Bristow

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Performance Analysis Of Cutting Graphite-Epoxy Composite Using A 90,000 Psi Abrasive Waterjet, Aiswarya Choppali Jan 2014

Performance Analysis Of Cutting Graphite-Epoxy Composite Using A 90,000 Psi Abrasive Waterjet, Aiswarya Choppali

Masters Theses

"Graphite-epoxy composites are being widely used in many aerospace and structural applications because of their properties: which include lighter weight, higher strength to weight ratio and a greater flexibility in design. However, the inherent anisotropy of these composites makes it difficult to machine them using conventional methods. To overcome the major issues that develop with conventional machining such as fiber pull out, delamination, heat generation and high tooling costs, an effort is herein made to study abrasive waterjet machining of composites. An abrasive waterjet is used to cut 1" thick graphite epoxy composites based on baseline data obtained from the ...


An Effectiveness - Based Analysis Of Ground Coupled Heat Exchangers, Chou Shen Jan 2014

An Effectiveness - Based Analysis Of Ground Coupled Heat Exchangers, Chou Shen

Masters Theses

"This thesis develops a theoretical framework, termed [Effectiveness] - BLU, to characterize the relation between temperatures, thermal contact and borehole length as it relates to the heat transfer processes in ground coupled heat exchangers used for ground source heat pump systems.

Borehole outflow temperature depends on the inflow temperature, the heat imposed on the borehole and the temperature history of the ground. In addition, variation of outflow temperature influences inflow temperature, even for the case of constant heat pump load. Because of this kind of feedback, the borehole inflow temperature may not be constant even with a fixed building load. Considering ...


Performance Evaluation Of Coaxial Horizontal Axis Hydrokinetic Turbines System, Abdulaziz M. Abutunis Jan 2014

Performance Evaluation Of Coaxial Horizontal Axis Hydrokinetic Turbines System, Abdulaziz M. Abutunis

Masters Theses

"Hydrokinetic energy technologies are emerging as a viable solution for renewable power generation. Unlike conventional hydropower turbines, hydrokinetic turbines are environmentally friendly; they operate at zero-head, and do not need dams to preserve the water. Unfortunately, they have a low efficiency which makes their design a challenging task. This work was focused on the hydrodynamic performance of horizontal axis hydrokinetic turbines (HAHkTs) under different turbine arrangements and flow conditions.

It was undertaken in an effort to improve the efficiency of small HAHkTs that harness a river's kinetic energy. Four sets of experiments were performed in a water tunnel to ...


Numerical Analysis Of Thermal Stress And Deformation In Multi-Layer Laser Metal Deposition Process, Heng Liu Jan 2014

Numerical Analysis Of Thermal Stress And Deformation In Multi-Layer Laser Metal Deposition Process, Heng Liu

Masters Theses

"Direct metal deposition (DMD) has gained increasing attention in the area of rapid manufacturing and repair. It has demonstrated the ability to produce fully dense metal parts with complex internal structures that could not be achieved by traditional manufacturing methods. However, this process involves extremely high thermal gradients and heating and cooling rates, resulting in residual stresses and distortion, which may greatly affect the product integrity. The purpose of this thesis is to study the features of thermal stress and deformation involved in the DMD process. Utilizing commercial finite element analysis (FEA) software ABAQUS, a 3-D, sequentially coupled, thermo-mechanical model ...


A Driving Simulator Study To Evaluate The Impact Of Portable Changeable Message Signs (Pcms) On Driver Speed Characteristics, Bharath Kolar Venkat Jan 2014

A Driving Simulator Study To Evaluate The Impact Of Portable Changeable Message Signs (Pcms) On Driver Speed Characteristics, Bharath Kolar Venkat

Masters Theses

"This research project examined the effects of sequential Portable Changeable Message Signs (PCMS) on driver behavior in work zones. PCMS are temporary traffic control (TTC) devices, part of Intelligent Transportation Systems, which supplement static signs to provide advance warning and real-time information to drivers. Text and number based messages are displayed on the PCMS for which detailed evaluation has not been carried out before. This research fills this gap using a driving simulator (DS) supplemented by objective and subjective surveys. A work zone on I-44 in rural Missouri was replicated in the DS using video recordings and GIS (Geographical Information ...


Comparison Of Magnetic Probe Calibration At Nano And Millitesla Magnitudes, Ryan A. Pahl, Joshua L. Rovey, David Pommerenke Jan 2014

Comparison Of Magnetic Probe Calibration At Nano And Millitesla Magnitudes, Ryan A. Pahl, Joshua L. Rovey, David Pommerenke

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Magnetic field probes are invaluable diagnostics for pulsed inductive plasma devices where field magnitudes on the order of tenths of tesla or larger are common. Typical methods of providing a broadband calibration of Ḃ probes involve either a Helmholtz coil driven by a function generator or a network analyzer. Both calibration methods typically produce field magnitudes of tens of microtesla or less, at least three and as many as six orders of magnitude lower than their intended use. This calibration factor is then assumed constant regardless of magnetic field magnitude and the effects of experimental setup are ignored. This work ...


Crystallization In Nano-Confinement Seeded By A Nanocrystal -- A Molecular Dynamics Study, Heng Pan, Costas Grigoropoulos Jan 2014

Crystallization In Nano-Confinement Seeded By A Nanocrystal -- A Molecular Dynamics Study, Heng Pan, Costas Grigoropoulos

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Seeded crystallization and solidification in nanoscale confinement volumes have become an important and complex topic. Due to the complexity and limitations in observing nanoscale crystallization, computer simulation can provide valuable details for supporting and interpreting experimental observations. In this article, seeded crystallization from nano-confined liquid, as represented by the crystallization of a suspended gold nano-droplet seeded by a pre-existing gold nanocrystal seed, was investigated using molecular dynamics simulations in canonical (NVT) ensemble. We found that the crystallization temperature depends on nano-confinement volume, crystal orientation, and seed size as explained by classical two-sphere model and Gibbs-Thomson effect.


Fabrication Of Out-Of-Autoclave Bismaleimide Based Composite Laminates With Embedded Fiber Optic Sensors, Sudharshan Anandan Jan 2014

Fabrication Of Out-Of-Autoclave Bismaleimide Based Composite Laminates With Embedded Fiber Optic Sensors, Sudharshan Anandan

Masters Theses

"Composites are becoming the material of choice in applications where weight savings are critical, like aerospace structures. The common composites used are- Carbon/Epoxy and Carbon/Bismaleimide (BMI). BMI based systems are preferred in applications which involve operating temperatures higher than conventional epoxies. Carbon/BMI laminates are traditionally fabricated in an autoclave, which is associated with high operating costs. In this work, a low cost out of autoclave (OOA) process is evaluated. It is desirable to have BMI OOA prepreg systems cure at reasonably low temperatures with sufficient degree of cure and green strength to maintain rigidity for subsequent freestanding ...


Modeling And Simulation Of Hydrokinetic Composite Turbine System, Haifeng Li Jan 2014

Modeling And Simulation Of Hydrokinetic Composite Turbine System, Haifeng Li

Doctoral Dissertations

"The utilization of kinetic energy from the river is promising as an attractive alternative to other available renewable energy resources. Hydrokinetic turbine systems are advantageous over traditional dam based hydropower systems due to "zero-head" and mobility. The objective of this study is to design and analyze hydrokinetic composite turbine system in operation. Fatigue study and structural optimization of composite turbine blades were conducted. System level performance of the composite hydrokinetic turbine was evaluated. A fully-coupled blade element momentum-finite element method algorithm has been developed to compute the stress response of the turbine blade subjected to hydrodynamic and buoyancy loadings during ...


Modeling And Simulation Of Continuous Fiber-Reinforced Ceramic Composites, Venkata Bheemreddy Jan 2014

Modeling And Simulation Of Continuous Fiber-Reinforced Ceramic Composites, Venkata Bheemreddy

Doctoral Dissertations

"Finite element modeling framework based on cohesive damage modeling, constitutive material behavior using user-material subroutines, and extended finite element method (XFEM), are developed for studying the failure behavior of continuous fiber-reinforced ceramic matrix composites (CFCCs) by the example of a silicon carbide matrix reinforced with silicon carbide fiber (SiC/SiCf) composite. This work deals with developing comprehensive numerical models for three problems: (1) fiber/matrix interface debonding and fiber pull-out, (2) mechanical behavior of a CFCC using a representative volume element (RVE) approach, and (3) microstructure image-based modeling of a CFCC using object oriented finite element analysis (OOF). Load versus ...


Performance Evaluation Of Polyurethane Composites Using Vacuum Infusion Process, Mohaned M. Mohamed Jan 2014

Performance Evaluation Of Polyurethane Composites Using Vacuum Infusion Process, Mohaned M. Mohamed

Doctoral Dissertations

"Glass fiber-reinforced polymer composites have promising applications in infrastructures due to their low cost, high specific stiffness/strength, and corrosion resistance. The pultrusion process is often used to manufacture glass fiber-reinforced polyurethane (PU) composite. The objective of this study is to use thermoset PU resin to manufacture high quality composites for infrastructure applications using vacuum assisted resin transfer molding (VARTM) process. Using VARTM to fabricate PU resins presents unique challenges. Several modifications however have helped with overcoming these problems. In part I of the research, the mechanical performance of two different PU resin not only evaluated but also compared to ...


Probabilistic Engineering Analysis And Design Under Time-Dependent Uncertainty, Zhen Hu Jan 2014

Probabilistic Engineering Analysis And Design Under Time-Dependent Uncertainty, Zhen Hu

Doctoral Dissertations

"Time-dependent uncertainties, such as time-variant stochastic loadings and random deterioration of material properties, are inherent in engineering applications. Not considering these uncertainties in the design process may result in catastrophic failures after the designed products are put into operation. Although significant progress has been made in probabilistic engineering design, quantifying and mitigating the effects of time-dependent uncertainty is still challenging. This dissertation aims to help build high reliability into products under time-dependent uncertainty by addressing two research issues. The first one is to efficiently and accurately predict the time-dependent reliability while the second one is to effectively design the time-dependent ...


Impact Of Fracture Spacing And Mechanical Parameter Anisotropy On Fracture Width In Horizontal Wells In Shales, Deepak Gokaraju Jan 2014

Impact Of Fracture Spacing And Mechanical Parameter Anisotropy On Fracture Width In Horizontal Wells In Shales, Deepak Gokaraju

Masters Theses

"The success of economically viable production of oil and gas from ultra-low permeability shale reservoirs depends on the creation of an extensive fracture network through hydraulic fracture stimulation. Multiple hydraulic fractures are created simultaneously in each stage to increase the surface area of contact between the wellbore and reservoir. The spacing between fractures is an important component to consider when developing an optimum stimulation design. An important aspect of shale rock properties is that shales are inherently anisotropic with a horizontal plane of isotropy (transversely isotropic) due to their finely layered structure. This study aims to provide an insight into ...


Effect Of Stress Concentrations On Fatigue Of Composite And Metallic Structures, Ross Henry Falen Jan 2014

Effect Of Stress Concentrations On Fatigue Of Composite And Metallic Structures, Ross Henry Falen

Masters Theses

"The complex shapes of hydrokinetic turbine blades can include part features such as a fillet, step, or hole. Situations can arise where two part features, such as a hole and a fillet, may be in close proximity which can introduce stress concentrations within the blade structure, adversely affecting the structure's life. Because the interaction between the part features isn't well known, fatigue data is needed to determine the proper analysis.

In this thesis, two separate topics are discussed and investigated. The first topic deals with stress concentrations in hydrokinetic turbine blades. Several blade designs were tested and improved ...


Modelling Of Directed Energy Deposition Processes, Xueyang Chen Jan 2014

Modelling Of Directed Energy Deposition Processes, Xueyang Chen

Masters Theses

"The laser additive manufacturing technique of laser deposition allows quick fabrication of fully-dense metallic components directly from Computer Aided Design (CAD) solid models. The applications of laser deposition include rapid prototyping, rapid tooling and part refurbishment. The development of an accurate predictive model for laser deposition is extremely complicated due to the multitude of process parameters and materials properties involved. In this work, a heat transfer and fluid flow model is developed.

In the heat transfer and fluid flow model, the governing equations for solid, liquid and gas phases in the calculation domain have been formulated using the continuum model ...


Additive Manufacturing Laser Deposition Of Ti-6al-4v For Aerospace Repair Application, Nanda Kumar Dey Jan 2014

Additive Manufacturing Laser Deposition Of Ti-6al-4v For Aerospace Repair Application, Nanda Kumar Dey

Masters Theses

"Parts or products machined from high performance metals are very expensive, partly due to the processing complexities during manufacturing. Therefore, many high performance metal parts users, such as the aerospace industry, mold/die casting industry, heavy machinery consumers etc., extend the service of these damaged parts by employing repair or remanufacturing technology. The research objective is to use laser deposition and machining processes to repair titanium parts.

This thesis discusses a new way of approach for developing a repair process for Ti-6Al-4V for the aerospace industry using Laser Metal Deposition (LMD). The repairs were conducted in a multi-axis hybrid manufacturing ...


Characterization Of 304l Stainless Steel By Means Of Minimum Input Energy On The Selective Laser Melting Platform, Ben Brown Jan 2014

Characterization Of 304l Stainless Steel By Means Of Minimum Input Energy On The Selective Laser Melting Platform, Ben Brown

Masters Theses

"Developing parameter sets for new materials on the Selective Laser Melting (SLM) platform has traditionally been done through the use of single line processing windows and a basic design of experiments (DOE) which would include varying machine parameters to maximize density. This study expands the traditional method by determining the main effects statistically for density, allowing for a more in depth analysis wherein the experimental results are statistically correlated to the variable machine parameters used. With this analysis, parameter optimization with respect to achieving near full density, while also considering build rates, can be performed. New parameters for 304L stainless ...


An Interactive Product Development Model In Remanufacturing Environment: A Chaos-Based Artificial Bee Colony Approach, Vishwa V. Kumar Jan 2014

An Interactive Product Development Model In Remanufacturing Environment: A Chaos-Based Artificial Bee Colony Approach, Vishwa V. Kumar

Masters Theses

"This research presents an interactive product development model in re-manufacturing environment. The product development model defined a quantitative value model considering product design and development tasks and their value attributes responsible to describe functions of the product. At the last stage of the product development process, re-manufacturing feasibility of used components is incorporated. The consummate feature of this consideration lies in considering variability in cost, weight, and size of the constituted components depending on its types and physical states.

Further, this research focuses on reverse logistics paradigm to drive environmental management and economic concerns of the manufacturing industry after the ...


Organizing A Student Poster Session In An Asee Section Conference, Steve Eugene Watkins, Les Kinsler, Julia L. Morse, Douglas R. Carroll Jan 2014

Organizing A Student Poster Session In An Asee Section Conference, Steve Eugene Watkins, Les Kinsler, Julia L. Morse, Douglas R. Carroll

Electrical and Computer Engineering Faculty Research & Creative Works

Student poster sessions at conferences can be valuable experiences for undergraduate and graduate students and can enrich the conference program for all participants. Student poster presentations beyond the local campus can provide additional experience in professional communication (especially in preparing succinct abstracts and in effective visual design), can prepare students for future conference participations, and can facilitate student-faculty interaction. Several issues exist when including student poster sessions in engineering education conferences. How can the content of posters be related to an engineering education theme? How are communication principles of audience and purpose incorporated into the session guidelines and review process ...


Nonlinear Development And Secondary Instability Of Traveling Crossflow Vortices, Fei Li, Meelan M. Choudhari, Lian Duan, Chau-Lyan Chang Jan 2014

Nonlinear Development And Secondary Instability Of Traveling Crossflow Vortices, Fei Li, Meelan M. Choudhari, Lian Duan, Chau-Lyan Chang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Building upon the prior research targeting the laminar breakdown mechanisms associated with stationary crossflow instability over a swept-wing configuration, this paper investigates the secondary instability of traveling crossflow modes as an alternate scenario for transition. For the parameter range investigated herein, this alternate scenario is shown to be viable unless the initial amplitudes of the traveling crossflow instability are lower than those of the stationary modes by considerably more than one order of magnitude. The linear growth predictions based on the secondary instability theory are found to agree well with both parabolized stability equations and direct numerical simulation, and the ...