Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Computer-Aided Engineering and Design (36)
- Materials Science and Engineering (35)
- Other Mechanical Engineering (35)
- Applied Mechanics (33)
- Acoustics, Dynamics, and Controls (30)
-
- Manufacturing (28)
- Automotive Engineering (23)
- Electrical and Computer Engineering (19)
- Physical Sciences and Mathematics (18)
- Engineering Science and Materials (17)
- Aerospace Engineering (15)
- Controls and Control Theory (15)
- Biomedical Engineering and Bioengineering (12)
- Computer Engineering (12)
- Heat Transfer, Combustion (12)
- Biomechanical Engineering (11)
- Electro-Mechanical Systems (10)
- Mechanics of Materials (10)
- Robotics (10)
- Navigation, Guidance, Control, and Dynamics (9)
- Other Materials Science and Engineering (9)
- Computational Engineering (8)
- Operations Research, Systems Engineering and Industrial Engineering (8)
- Structural Materials (8)
- Civil and Environmental Engineering (7)
- Physics (7)
- Energy Systems (6)
- Engineering Mechanics (6)
- Keyword
-
- Optimization (11)
- Finite element analysis (7)
- Robotics (7)
- Machine Learning (6)
- Microfluidics (6)
-
- Fatigue (5)
- Honeycomb (5)
- Machine learning (5)
- Manufacturing (5)
- Additive manufacturing (4)
- CAD (4)
- CFD (4)
- Combustion (4)
- Composite (4)
- Composites (4)
- Creep (4)
- Design (4)
- Electrophoresis (4)
- Finite Element Analysis (4)
- Nanocomposites (4)
- Simulation (4)
- Vibration (4)
- Viscoelasticity (4)
- Additive Manufacturing (3)
- CAE chain (3)
- CFRP (3)
- Collaboration (3)
- Computational fluid dynamics (3)
- Conceptual Design (3)
- Controls (3)
- Publication Year
- Publication
- Publication Type
Articles 271 - 300 of 371
Full-Text Articles in Mechanical Engineering
Computational Modeling Of The Friction Stir Welding (Fsw) Process And Of The Performance Of Fsw Joints, Ajay Prasad Arakere
Computational Modeling Of The Friction Stir Welding (Fsw) Process And Of The Performance Of Fsw Joints, Ajay Prasad Arakere
All Theses
Friction Stir Welding (FSW) is a solid-state metal-joining process. Within FSW, a (typically) cylindrical tool-pin (threaded at the bottom and terminated with a circular-plate shape shoulder, at the top) is driven between two firmly-clamped plates (placed on a rigid backing support). Due to a high normal downward pressure applied to the shoulder and due to frictional sliding and plastic-deformation, substantial amount of heat is generated at the tool/work-piece interface and in the region underneath the tool shoulder. Thermally plasticized work-piece material is then extruded around the traveling tool and forged into a welding-joint behind the tool. Due to its solid-state …
Modal Analysis To Minimize Gearbox Induced Noise Of General Electric Wind Turbines, Matthew Evans
Modal Analysis To Minimize Gearbox Induced Noise Of General Electric Wind Turbines, Matthew Evans
All Theses
With the current global emphasis on alternative green energy sources, wind turbine technologies have seen significant growth in recent years. Today, wind turbines are being produced and constructed at unprecedented levels with their sites inching closer and closer to residential communities. With that, wind turbine companies have been receiving growing complains about the noise emitted from these turbines during operation. To resolve this issue, many of these companies are spending more resources to design and manufacture quieter wind turbines. In particular, General Electric (GE) intends to reduce the noise created by their 2.5 MW CGDT wind turbines. Previous studies showed …
Laser-Assisted Printing Of Alginate And Cellular Tubes, Jingyuan Yan
Laser-Assisted Printing Of Alginate And Cellular Tubes, Jingyuan Yan
All Theses
Laser-assisted printing such as laser-induced forward transfer (LIFT) has found increasing biofabrication applications as an orifice-free cell/organ printing approach. Unfortunately, there have been very few studies on its efficacy of three-dimensional (3D) printing performance. In addition, the effects of printing parameters on jet/droplet formation during the printing of Newtonian and non-Newtonian fluids are lacking. Therefore, it is important to investigate its printing process and quality. The resulting knowledge will help to better control the resulting printing quality and feature resolution.
The objective of this study is to investigate the feasibility of laser-assisted 3D printing process and its applicability in making …
A Model-Free Approach To Vehicle Stability Control, Chinmay Pandit
A Model-Free Approach To Vehicle Stability Control, Chinmay Pandit
All Theses
This project explored the feasibility of using measured responses of a passenger car together with a fuzzy logic based control algorithm to sense the onset of under-steer (or loss of steering control) and mitigate or eliminate it. The controller is simple and robust and, unlike existing controllers, instead of comparing the vehicle response to that of an idealized model it makes decisions based solely upon the measured response of the car.
Simulations were conducted (using CarSim) of various vehicles executing the skid pad and the double lane change tests to characterize the vehicle behavior. Consistent and qualitatively similar patterns in …
An Experimental Study On The Influence That Failure Number, Specialization, And Domain Have On Confidence In Predicting System Failures, Somaiah Thimmaiah
An Experimental Study On The Influence That Failure Number, Specialization, And Domain Have On Confidence In Predicting System Failures, Somaiah Thimmaiah
All Theses
Design reviews are typically used for three types of design activities: 1) identifying errors, 2) assessing the impact of the errors, and 3) suggesting solutions for the errors. This experimental study focuses on understanding the second issue as it relates to the number of errors considered, the existence of controls, and the level of domain familiarity of the assessor. A set of design failures and associated controls developed for a completed industry sponsored project is used as the experimental design problem. Non-domain individuals (psychology class students), domain generalists (first year engineering students), and domain specialists (graduate mechanical students) are provided …
Identification Of And Effects On The Depth Of The Machining Affected Zone In Nickel-Based Superalloys, Boyce Richardson
Identification Of And Effects On The Depth Of The Machining Affected Zone In Nickel-Based Superalloys, Boyce Richardson
All Theses
The formation of subsurface damage during machining of nickel-based superalloys is a critical quality concern for the manufacture of gas turbine components. The identification and understanding of this zone are critical to the reduction of destructive testing and scrap costs in an ever changing manufacturing environment. This thesis seeks to provide a novel objective method for identification of the depth of this zone and an empirical model for the effects of machining parameters on this zone. This allows for optimal machining parameters to be used in manufacturing reducing the need for destructive testing, while also reducing manufacturing costs by reducing …
Understanding The Role Of Nonlinearities In The Transduction Of Vibratory Energy Harvesters, Ravindra Masana
Understanding The Role Of Nonlinearities In The Transduction Of Vibratory Energy Harvesters, Ravindra Masana
All Dissertations
The last two decades have witnessed several advances in micro-fabrication technologies and electronics, leading to the development of small, low-power devices for wireless sensing, data transmission, actuation, and medical implants. Unfortunately, the actual implementation of such devices in their respective environment has been hindered by the lack of scalable energy sources that are necessary to power and maintain them. Batteries, which remain the most commonly used power source, have not kept pace with the demands of these devices, especially in terms of energy density. In light of this challenge, the concept of vibratory energy harvesting has flourished in recent years …
Prediction Of Discrete Element Parameters For Modeling The Strength Of Sandy Soils In Wheel/Soil Traction Applications, Timothy Reeves
Prediction Of Discrete Element Parameters For Modeling The Strength Of Sandy Soils In Wheel/Soil Traction Applications, Timothy Reeves
All Dissertations
The problem of wheel performance on deformable soil has been studied for many years, but prior to the rise of computational mechanics, such investigations have been limited to development of analytical and empirical models, as well as experimental research. Such models have merit but are necessarily highly idealized and are limited in their applications. Today, many computational models have been implemented for a wide variety of wheel/soil applications.
For the specific case of sandy (i.e. non-cohesive) soils, in terms of the soil's physics the Discrete Element Method (DEM) provides arguably the most realistic model. In DEM, each element represents a …
Magnetic Manipulation Of Particles And Cells In Ferrofluid Flow Through Straight Microchannels Using Two Magnets, Jian Zeng
All Theses
Microfluidic devices have been increasingly used in the past two decades for particle and cell manipulations in many chemical and biomedical applications. A variety of force fields have been demonstrated to control particle and cell transport in these devices including electric, magnetic, acoustic, and optical forces etc. Among these particle handling techniques, the magnetic approach provides clear advantages over others such as low cost, noninvasive, and free of fluid heating issues. However, the current knowledge of magnetic control of particle transport is still very limited, especially lacking is the handling of diamagnetic particle. This thesis is focused on the magnetic …
Design Of An Apparatus To Detect Small Changes In The Mass Of Rotational Machine Components, Jonathan R.A. Maier, M. Laine Mears, Joshua D. Summers
Design Of An Apparatus To Detect Small Changes In The Mass Of Rotational Machine Components, Jonathan R.A. Maier, M. Laine Mears, Joshua D. Summers
Publications
In this study, an apparatus was designed to detect changes on the order of grams in the mass of test samples subject to accelerations approaching 275g. The apparatus incorporated a surface speedometer, displacement transducer and on-board data-logging device in order to correlate mass loss events with changes in rotational speed and acceleration. An accessory was also designed to allow for on-board video recording to validate the findings and to better understand the mechanics of mass loss events. Such mass loss events are of interest for high-speed rotating machinery (e.g., manufacturing equipment, turbine rotors and automotive drivetrains), where material can build …
Development Of Feature Recognition Algorithm For Automated Identification Of Duplicate Geometries In Cad Models, Aravind Shanthakumar
Development Of Feature Recognition Algorithm For Automated Identification Of Duplicate Geometries In Cad Models, Aravind Shanthakumar
All Theses
This research presents a feature recognition algorithm for the automated identification of duplicate geometries in the CAD assembly. The duplicate geometry is one of the seven indicators of the lazy parts mass reduction method. The lazy parts method is a light weight engineering method that is used for analyzing parts with the mass reduction potential. The duplicate geometry is defined as any geometries lying equal to or within the threshold distance with the user-defined orientation between them and have the percentage similarity that is equal to or greater than the threshold value. The feature recognition system developed in this research …
Design Automation And Optimization Of Honeycomb Structures For Maximum Sound Transmission Loss, Rohan Galgalikar
Design Automation And Optimization Of Honeycomb Structures For Maximum Sound Transmission Loss, Rohan Galgalikar
All Theses
Cellular materials with macro effective properties defined by repeated meso-structures are increasingly replacing conventional homogeneous materials due to their high strength to weight ratio, and controllable effective mechanical properties, such as negative Poisson's ratio and tailored orthotropic elastic properties. Honeycomb structures are a well-known cellular material that has been used extensively in aerospace and other industries where the premium on the weight reduction with high-strength is required. Common applications of honeycomb cellular structures are their use as the core material in sandwich plates and plates between two face sheets. Honeycomb structures are built from repetition of a common hexagonal unit …
Alternative Energy Sources - Integration Of Power Generation Systems Into A Microgrid At Clemson University And An Atmospheric Thermodynamic Driven Mechanical Clock, Shreyas Patel
All Theses
Non-renewable energy sources such as coal, crude oil, and natural gas are being consumed at a brisk pace which is promoting a worldwide energy crisis. The burning of fossil fuels produces greenhouse gases such as carbon dioxide and nitrous oxides as well as soot which contribute to atmospheric pollution. Although fossil fuels will continue to be available for many decades, the amount of petroleum remaining in the earth and its associated cost remains an open issue. The utilization of green energy such as solar and wind offer renewable and pollution free sources. A worldwide shift is slowly underway towards the …
Standardization Of Process Sheet Information To Support Automated Translation Of Assembly Instructions And Product-Process Coupling, Matthew Peterson
Standardization Of Process Sheet Information To Support Automated Translation Of Assembly Instructions And Product-Process Coupling, Matthew Peterson
All Theses
The design and manufacture of large scale systems, particularly automobiles, is a process that requires collaboration across multiple disciplines. This collaboration is facilitated through efficient and effective data and knowledge storage and transfer. Specifically, the data associated with the final assembly of the vehicle should be generated, organized, and distributed in such a manner that each user of the data is able to use it effectively. Furthermore, the structure for the assembly data should be robust and reliable such that it fosters consistency among various planners for multiple vehicle platforms that are assembled all around the world. This research aims …
Development Of A Two-Dimensional Model Of A Pneumatic Tire, Timothy Lewis
Development Of A Two-Dimensional Model Of A Pneumatic Tire, Timothy Lewis
All Theses
The pneumatic tire has been studied extensively since its invention in 1888. With the advent of high-powered computers and the use of the finite element method, the understanding of the tire's complex non-linear behavior has grown tremendously. However, one weakness of finite element models is that parameter studies are difficult and time consuming to perform. In contrast, an analytical model can quickly and easily perform extensive parameter studies. To the knowledge of the author, all existing analytical models of the tire make assumptions concerning the tire's behavior and construction that while useful for obtaining some of the first-order characteristics, are …
Composite Sandwich Structures With Honeycomb Core Subjected To Impact, Lei He
Composite Sandwich Structures With Honeycomb Core Subjected To Impact, Lei He
All Theses
Composite sandwich structures constructed with honeycomb core can be an effective means of absorbing impact in many engineer applications. Conventional hexagonal honeycomb exhibit an effective positive Poisson's ratio, are commonly employed due to their lightweight and high axial stiffness properties. In contrast, auxetic honeycombs offer high in-plane shear stiffness, and exhibit negative Poisson's ratios with lateral extension, instead of contraction, when stretched axially.
In this study, the dynamic response of an aluminum composite panel with a honeycomb core constrained within two thin face sheets is investigated undergoing impact with a rigid ball. The finite element models used to simulate impact …
Concept Generation Using Morphological And Options Matrices, Dani George
Concept Generation Using Morphological And Options Matrices, Dani George
All Theses
The use of morphological matrices as a tool to aid concept generation is examined. Two limitations of the method are highlighted; (1) the large number of potential combinatorial possibilities and (2) the lack of design details in the system concepts generated. An Integrated Idea Generation (IIG) method is proposed to support the generation of detailed system concepts effectively without performing a full factorial combination of the means within a morphological matrix. Pairwise functional combinations are extracted from the functions listed in the morphological matrix and explored in detail using options matrices and innovation challenges, encouraging designers to identify implicit assumptions …
Study Of Cell Viability During Laser Direct Writing Of Cell-Alginate Suspension, Hemanth Gudapati
Study Of Cell Viability During Laser Direct Writing Of Cell-Alginate Suspension, Hemanth Gudapati
All Theses
Laser-assisted cell printing, developed based on Matrix-assisted pulsed-laser evaporation direct-write (MAPLE DW), a typical LIFT (laser-induced forward transfer) practice, has been emerging as one of the most promising biofabrication techniques. Alginate, particularly sodium alginate, is extensively used as the constituent of bioink in laser-assisted cell printing. However, thus far, studies investigating the effect of alginate gelation on cell viability in laser-assisted cell printing are lacking. The objective of this study is to investigate the effects of gelation, gelation time, sodium alginate concentration, and the effect of operating conditions such as the laser fluence on post-transfer cell viability during laser-assisted cell …
Network Target Coordination For Design Optimization Of Decomposed Systems, Wenshan Wang
Network Target Coordination For Design Optimization Of Decomposed Systems, Wenshan Wang
All Dissertations
A complex engineered system is often decomposed into a number of different subsystems that interact on one another and together produce results not obtainable by the subsystems alone. Effective coordination of the interdependencies shared among these subsystems is critical to fulfill the stakeholder expectations and technical requirements of the original system. The past research has shown that various coordination methods obtain different solution accuracies and exhibit different computational efficiencies when solving a decomposed system. Addressing these coordination decisions may lead to improved complex system design. This dissertation studies coordination methods through two types of decomposition structures, hierarchical, and nonhierarchical.
For …
On Simulation And Modeling Of Turbulent Non-Premixed Reacting Shear Flames At Low And High Pressure, Justin Foster
On Simulation And Modeling Of Turbulent Non-Premixed Reacting Shear Flames At Low And High Pressure, Justin Foster
All Dissertations
A database of simulations of fundamental turbulent H2/O2 and H2/Air shear layer flames has been developed using the direct numerical simulation technique in which all length and time scales of a flow are fully resolved without resort to turbulence modeling. The formulation includes the fully-compressible form of the governing equations, a pressure dependent detailed chemical kinetics scheme (9 species, 19 steps), a cubic real gas equation of state, realistic property models, and generalized heat and mass diffusion models. Simulations were conducted for a temporally developing shear layer geometry and cover a wide range of initial pressures (1 atm < P < 125 atm) and flame Reynolds numbers (850 < Re < 4500). These supercomputing simulations are the largest yet performed for high pressure conditions to the author's knowledge. Computational requirements for the largest simulations included mesh sizes of ~3/4 billion grid points and ~2.2 million CPU-hrs conducted on nearly 4,000 CPU cores on Clemson's Palmetto cluster.
The database …
An Electromagnetic Energy Harvester For Powering Consumer Electronics, Xiyuan Liu
An Electromagnetic Energy Harvester For Powering Consumer Electronics, Xiyuan Liu
All Theses
This thesis introduces an electromagnetic vibratory energy harvester to power consumer electronics by generating electricity from the strides taken during walking or jogging. The harvester consists of a magnetic pendulum oscillating between two fixed magnets. The pendulum behaves similar to a rotor in a DC generator, while the fixed magnets, which are poled opposite to the pendulum, provide magnetic restoring forces similar to mechanical springs. When attached to a person's arm, the swinging motion subjects the magnetic pendulum to base excitations. Consequently, the pendulum oscillates near a stator which has three poles of wound copper coils. The motion of the …
Vibration And Acoustic Performance Of In-Plane Honeycomb Sandwich Panels, Xiao Gong
Vibration And Acoustic Performance Of In-Plane Honeycomb Sandwich Panels, Xiao Gong
All Theses
Sandwich panel structures constructed with cellular honeycomb cores allow for control of acoustic performance due to their ability to optimize effective orthotropic material properties with changes in cell geometry. By modification of topology and geometric parameters of a unit cell, desirable effective properties can be obtained and used to design lightweight structures with reduced vibration and increased sound transmission loss properties. Thus investigating the relation between the geometric configuration of the honeycomb core and vibration and acoustic behavior is important to optimize design of sandwich panels.
In this work, a finite element model is developed in MATLAB to evaluate the …
Model Of A Mechanical Clock Escapement, John Wagner, David Moline, Eugene Vold
Model Of A Mechanical Clock Escapement, John Wagner, David Moline, Eugene Vold
Publications
The mechanical tower clock originated in Europe during the 14th century to sound hourly bells and later display hands on a dial. An important innovation was the escapement mechanism, which converts stored energy into oscillatory motion for fixed time intervals through the pendulum swing. Previous work has modeled the escapement mechanism in terms of inelastic and elastic collisions. We derive and experimentally verify a theoretical model in terms of impulsive differential equations for the Graham escapement mechanism in a Seth Thomas tower clock. The model offers insight into the clock’s mechanical behavior and the functionality of the deadbeat escapement mechanism.
Design Of Meta-Materials Outside The Homogenization Limit Using Multiscale Analysis And Topology Optimization, Christopher Czech
Design Of Meta-Materials Outside The Homogenization Limit Using Multiscale Analysis And Topology Optimization, Christopher Czech
All Dissertations
The field of meta-materials engineering has largely expanded mechanical design possibilities over the last two decades; some notable design advances include the systematic engineering of negative Poisson's ratio materials and functionally graded materials, materials designed for optimal electronic and thermo-mechanical performances, and the design of materials under uncertainty. With these innovations, the systematic engineering of materials for design-specific uses is becoming more common in industrial and military uses. The motivation for this body of research is the design of the shear beam for a non-pneumatic wheel. Previously, a design optimization of a finite element model of the non-pneumatic wheel was …
Compressive Strength Of Continuous Fiber Unidirectional Composites, Ronald Thompson
Compressive Strength Of Continuous Fiber Unidirectional Composites, Ronald Thompson
All Dissertations
Dow and Rosen's work in 1965 formed an intellectual framework for compressive strength of unidirectional composites. Compressive strength was explained in terms of micro-buckling, in which filaments are beams on an elastic foundation. They made simplifying assumptions, with a two dimensional idealization and linearized material properties. This study builds on their model, recognizing that the shear mode of instability drives unidirectional compressive strength. As a necessary corollary, the predictive methods developed in this study emphasize correct representation of composite shear stiffness. Non-linear effects related to matrix material properties, fiber misalignment, three dimensional representation, and thermal prestrains are taken into account. …
Qualified Affordance-Based Design, Jun Hu
Qualified Affordance-Based Design, Jun Hu
All Theses
Function-based approaches are taught by the engineering design community and implemented in practice. The most significant advantage of these approaches is that they can guide the designers to abstract the essential problems from the design requirements, build the function-based models, and consequently provide the direction of the solution. However, due to the lack of a consistent scientific definition on the meaning of the function, these approaches may be contradictory when representing human-centered aspects, features, and non-physical purposes. To address this issue, design researchers have pursued two general directions: (1) broadening the meaning of function and (2) introducing an alternative scientific …
A Case Study In Challenging And Validating Engineering Requirements With Value-Based Techniques, Seth Crouch
A Case Study In Challenging And Validating Engineering Requirements With Value-Based Techniques, Seth Crouch
All Theses
Requirements are an essential element to engineering design as they are used to focus idea generation during conceptual design, provide criteria for decision making during concept selection, and verify the chosen concept fulfills product needs. Because they are essential to the entire design process, great emphasis needs to be put on ensuring that they are correct. This research focuses on a value-based methodology useful for challenging and validating established requirements. A case study was conducted using this process on a project involving the design of a vehicle seat. This case study shows that this approach provides more persuasive evidence to …
Assessment Of A Safe Driving Program For Novice Drivers And Smart Jersey Barrier Design To Minimize Animal-To-Vehicle Collisions, Lance Clark
All Theses
Each year, the total number of vehicles, motorists, highway infrastructures, and distance traveled by drivers increases on a global basis. This rise in personal and commercial ground vehicle usage brings with it the advantages of the modern age, but it is not without societal cost. Vehicular incidents result in tens of thousands of deaths each year in the United States alone. For this reason, research has been performed to advance driver safety while simultaneously providing wildlife with means to avoid animal-to-vehicle collisions (AVC). In this thesis, two solutions are proposed: a driver education program with classroom experiences, in-vehicle resources, and …
Charging Kinetics Of Micropores In Supercapacitors, Daniel Oberklein
Charging Kinetics Of Micropores In Supercapacitors, Daniel Oberklein
All Theses
The charging kinetics of Electric Double Layer Capacitors (EDLC) were studied using a continuum model based on the Poisson-Nernst-Planck (PNP) Equations, with the additional modeling of the bulk fluid motion in the electrolyte using the Navier-Stokes Equations. The results demonstrate that the addition of bulk flow modeling yields a faster charging rate and higher charging current due to the additional convective component of the current resulting from the bulk fluid motion. A parametric study was conducted to determine the effect of various physical parameters of the EDLC system on the charging kinetics. Decreased fluid viscosity results in a faster charging …
Automated Assembly Time Prediction Tool Using Predefined Mates From Cad Assemblies, Joseph Owensby
Automated Assembly Time Prediction Tool Using Predefined Mates From Cad Assemblies, Joseph Owensby
All Theses
Current Design for Assembly (DFA) methods and tools require extensive amounts and types of user inputs to complete the analysis. Since the methods require extensive amounts and types of inputs, certain issues arise: the analysis can become tedious, time consuming, error prone, and not repeatable. These issues eventually lead to the DFA methods being used as a redesign tool or not being implemented at all.
The research presented in this thesis addresses the current DFA limitations and issues by developing and implementing an automated assembly time prediction tool that: extracts explicitly defined connections from SolidWorks assembly models, determines the structural …