Mechanical Engineering Commons^™

Multiscale Modeling Of Smart Materials Under Static And Dynamic Thermo-Mechanical Loading, Soodabeh Sharafi

LSU Master's Theses

Engineering material systems with tailored capabilities are a topic trend in plethora of research. Polymer based Artificial Muscle, PAM, and Shape memory polymer fiber, SMPF, enable structural engineers to incorporate smartness functionality into their design through programming cycles. Smartness functionality leads to the production of artificial muscles with different load carrying capability. SMPF is another category of smart materials, which are capable of being micro-structurally engineered to isolate vibration at different temperature and frequency conditions. The smartness functionality offers the adjustment between inherent properties of these materials with their industrial applications through modeling techniques. Mixture of phenomenological, numerical, mathematical models …

Mechatronic Education At The Faculty Of Technical Sciences Novi Sad, Gordana Ostojić, Vukica Jovanović, Drazan Kozak, Zeljko Ivandić, Stevan Stankovski

Engineering Technology Faculty Publications

The emerging engineering field of mechatronics has caught the attention of many engineering professionals, academics and government officials in recent years, nationally and globally. The main reason for this is that many modern products are no longer purely electrical and electronic or mechanical. Moreover, they are integrated multidisciplinary products which are made from subsystems which require engineering knowledge of different disciplines. Hence, increasing number of universities is offering courses, certificates and programs at undergraduate and graduate levels in the area of mechatronics. This paper presents an educational program in mechatronics at the Faculty of Technical Sciences, University of Novi Sad, …

An Analytic Solution Of The Thermal Boundary Layer At The Leading Edge Of A Heated Semi-Infinite Flat Plate Under Forced Uniform Flow, Robert Jessee

LSU Master's Theses

Abstract The heated flat plate under uniform flow has been vastly studied, with the Blasius and Pohlhausen solutions developed over 100 years ago. These solutions are numerical in nature. Here, an analytic solution is found for the temperature and velocity profiles at the leading edge of a heated flat plate under forced uniform flow. By defining a similarity variable the governing equations are reduced to a dimensionless equation with an analytic solution at the leading edge. This report gives justification for the similarity variable via scaling analysis, details the process of converting to similarity form, and presents a similarity solution. …

Study Of Active Vibration Control Using The Method Of Receptances, Amit Maha

LSU Doctoral Dissertations

Using the Method of Receptance, it is possible in general to assign 2_x0002_ poles (i.e. n conjugate pairs) of an axially vibrating rod of variable cross section by sensing the state at _x0002_ points along the rod. Using the sensor data, closed loop feedback control gains can be calculated by solving a simple set of linear equations. The feedback gains can be applied to generate the required control force using an actuator. This partial pole assignment can be done without continuous or discrete analytical modeling. Therefore, the physical parameters such as the rigidity, the density, and the variable cross-sectional area …

The Effects Of Work Zone Configurations On Physiological And Subjective Workload, Mahmoud Shakouri Hassanabadi

LSU Master's Theses

There is a dearth of research on the effect of driving through work zones on physiological and subjective workload of drivers. The objectives of this research were to (a) study the effect of work zones and traffic density on physiological measures of workload, subjective workload and performance variables (b) study the relationship between physiological measures of workload, subjective workload and performance variables. Conventional lane merge (CLM), joint lane merge (JLM) and a road without a work zone (control) were modeled with high and low traffic density by using a full-size driving simulator. 13 female and 17 male students volunteered to …

Challenges Towards Structural Integrity And Performance Improvement Of Welded Structures, Mohammad Washim Dewan

LSU Doctoral Dissertations

Welding is a fabrication process that joint materials, is extensively utilized in almost every field of metal constructions. Heterogeneity in mechanical properties, metallurgical and geometrical defects, post-weld residual stresses and distortion due to non-linear welding processes are prime concerns for performance reduction and failures of welded structures. Consequently, structural integrity analysis and performance improvement of weld joints are important issues that must be considered for structural safety and durability under loading. In this study, an extensive experimental program and analysis were undertaken on the challenges towards structural integrity analysis and performance improvement of different welded joints. Two widely used welding …

Development Of A Hydraulic Component Leakage Detecting System Using Pressure Decay Signal, Xuanju Shang

Dissertations and Theses @ UNI

It is preferable to detect leakage at the earliest phase in the manufacturing process, and then further assembly of hydraulic components with leakage problems can be avoided. Integrating a USB based microcontroller and a pressure sensor; this study developed a hydraulic leakage detection system in using air instead of hydraulic oil as medium, through measuring pressure decay signals captured by a real time data acquisition system. Compared with the conventional hydraulic system using oils, this system shows advantages in safety operation and little environmental concerns due to use a lower pressure clean air.

The low-cost hydraulic leakage detection system was …

Photonic Crystal Fibre Wgm Resonators For Magnetic Field Sensing, Aseel Mahmood, Vishnu Kavungal, Yuliya Semenova, S. S. Ahmed

Conference Papers

Whispering gallery mode (WGM) micro-resonators are remarkable optical devices whose small modevolumes and high Q-factors make them attractive for a wide range of applications such as filters, lasers, modulators and sensors [1]. WGMs can be excited in dielectric structures with circular symmetry, such as microspheres, micro-disks, and optical fibres, and can be imagined as closed-trajectory rays confined within the cavity by almost total reflections from the curved surface of the resonator. The spectral positions of the WGM resonances are highly sensitive to the geometrical dimensions of the resonator and refractive indices of both the resonator itself and its surrounding medium …

Development And Validation Of A New Blade Element Momentum Skewed-Wake Model Within Aerodyn, Andrew Ning, Greg Hayman, Rick Damiani, Jason Jonkman

Faculty Publications

Blade element momentum methods, though conceptually simple, are highly useful for analyzing wind turbines aerodynamics and are widely used in many design and analysis applications. A new version of AeroDyn is being developed to take advantage of new robust solution methodologies, conform to a new modularization framework for National Renewable Energy Laboratory’s FAST, utilize advanced skewed-wake analysis methods, fix limitations with previous implementations, and to enable modeling of highly flexible and nonstraight blades. This paper reviews blade element momentum theory and several of the options available for analyzing skewed inflow. AeroDyn implementation details are described for the benefit of users …

Self-Assembly Kinetics Of Microscale Components: A Parametric Evaluation, Jose Miguel Carballo

USF Tampa Graduate Theses and Dissertations

The goal of the present work is to develop, and evaluate a parametric model of a basic microscale Self-Assembly (SA) interaction that provides scaling predictions of process rates as a function of key process variables. At the microscale, assembly by “grasp and release” is generally challenging. Recent research efforts have proposed adapting nanoscale self-assembly (SA) processes to the microscale. SA offers the potential for reduced equipment cost and increased throughput by harnessing attractive forces (most commonly, capillary) to spontaneously assemble components. However, there are challenges for implementing microscale SA as a commercial process. The existing lack of design tools prevents …

A Numerical And Experimental Investigation Of Flow Induced Noise In Hydraulic Counterbalance Valves, Mutasim Mohamed Elsheikh

USF Tampa Graduate Theses and Dissertations

The main objective of this study is to explore the complex fluid flow phenomena that result in the generation of a high frequency noise in counterbalance valves through an experimental and numerical investigation of the flow. Once the influence of the different components involved in noise generation is established, a secondary objective is the introduction of design modifications that eliminate the undesired effect without altering the operation envelope or the performance of the valve.

A hydraulic test bench was used to carry out an experimental investigation of the noise generation process. A computer based data acquisition system was used to …

Use Of Anaerobic Adhesive For Prevailing Torque Locking Feature On Threaded Product, Alan Hernandez

USF Tampa Graduate Theses and Dissertations

The purpose of this research is to determine if anaerobic adhesive can be used as a prevailing torque locking feature. Maintaining preload in critical joints is the usual standard that anaerobic adhesives are held to in aerospace and other industry. To test if anaerobic adhesive can be used as a prevailing torque locking feature a test procedure was developed and implemented to measure the removal torque of threaded fasteners after an allotted cure time. In total, 191 threaded fasteners of different material and coatings were tested in the unseated and seated states with various strengths and varieties of anaerobic adhesive. …

A Planar Pseudo-Rigid-Body Model For Cantilevers Experiencing Combined Endpoint Forces And Uniformly Distributed Loads Acting In Parallel, Philip James Logan

USF Tampa Graduate Theses and Dissertations

This dissertation describes the development and effectiveness of a mathematical model used to predict the behavior of cantilever beams whose loading conditions include parallel combinations of evenly distributed loads and endpoint forces. The large deflection of cantilever beams has been widely studied. A number of models and mathematical techniques have been utilized in predicting the endpoint path coordinates and load-deflection relationships of such beams. The Pseudo-Rigid-Body Model (PRBM) is one such method which replaces the elastic beam with rigid links of a parameterized pivot location and torsional spring stiffness. In this paper, the PRBM method is extended to include cases …

Superconducting Magnetic Energy Storage Unit For Damping Enhancement Of A Wind Farm Generation System, Embaiya Salih, Stefan Lachowicz, Octavian Bass, Daryoush Habibi

Research outputs 2014 to 2021

A superconducting magnetic energy storage (SMES) system containsa high inducting coil and combines with power conversion system can act as a constant source of direct current. SMES unit connected to a power system is able to absorb and store both active and reactive power from this system and to inject these powers into the power system in the demand periods. These injected powers are controlled by changing both the duty cycle of the dc-dc chopper switches and its operation modes. This paper presents an efficient design based on an SMES unit controlled by the artificial neural network (ANN) to improve …

Experimental Investigation Of Encapsulated Phase Change Materials For Thermal Energy Storage, Tanvir E. Alam

USF Tampa Graduate Theses and Dissertations

Thermal energy storage (TES) is one of the most attractive and cost effective solutions to the intermittent generation systems like solar, wind and other renewable sources, compared to alternatives. It creates a bridge between the power supply and demand during peak hours or at times of emergency to ensure the continuous supply of energy. Among all the TES systems, latent heat thermal energy storage (LHTES) draws lots of interests as it has high energy density and can store or retrieve energy isothermally. Two major technical challenges associated with the LHTES are low thermal conductivity of the phase change materials (PCMs), …

Electrowetting Force And Velocity Dependence On Fluid Surface Energy, Qi Ni, Daniel E. Capecci, Nathan B. Crane

Faculty Publications

Electrowetting on Dielectric is a phenomenon in which the shape and apparent contact angle of a droplet changes when an electric field is applied across the droplet interface. If the field is asymmetric with respect to the droplet, then a net force can be applied to the droplet. In this work, we have measured the electrowetting force by confining the droplet shape beneath a glass plate and measuring the force on the plate. The force was measured as a function of voltage for a range of fluids with different surface energy. Measured forces show excellent agreement with predictions based on …

Stress-Limiting Test Structures For Rapid Low-Cost Strength And Stiffness Assessment, Andrew Katz, Craig P. Lusk, Nathan B. Crane

Faculty Publications

Purpose: Evaluate the use of a simple printed geometry to estimate mechanical properties (elastic modulus, yield strength) with inexpensive test equipment.

Design Methodology/Approach: Test geometry is presented that enables controlled strains with manual deformation and repeatable measurement of vibrational frequencies. This is tested with multiple FDM machines to assess measurement accuracy and repeatability. Printing orientation and some printing parameters are varied to assess the measurement sensitivity.

Findings: The test methods show good correlation with manufacturer material specifications in the X-Y plane and reported elastic strain limits. It is also sensitive to printing orientation and printing parameters.

Research Limitations/Implications: Further work …

Thick Rigidly Foldable Structures Realized By An Offset Panel Technique, Bryce Edmondson, Robert J. Lang, Michael R. Morgan, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Rigid-panel origami is often mathematically modeled with idealized zero-thickness panels. When paper is used to realize an origami design, the zero-thickness models are a good approximation. However, many origami-inspired designs require the use of thicker materials that likely will not behave as the zero-thickness kinematic models predict.

The offset panel technique defined previously by the authors [Edmondson et al. 14] maintains the kinematics of a zero-thickness origami source model over its full range of motion. The offset panel technique accommodates uniform and varying panel thickness as well as offset panels or gaps between panels. The preserved kinematic behavior allows designers …

Development And Operation Of A Mobile Test Facility For Education, Christopher Davis

Dissertations, Master's Theses and Master's Reports

The automotive industry saw a large shift towards vehicle electrification after the turn of the century. It became necessary to ensure that new and existing engineers were qualified to design and calibrate these new systems. To ensure this training, Michigan Tech received a grant to develop a curriculum based around vehicle electrification. As part of this agenda, the Michigan Tech Mobile Laboratory was developed to provide hands-on training for professional engineers and technicians in hybrid electric vehicles and vehicle electrification. The Mobile Lab has since then increased the scope of the delivered curriculum to include other automotive areas and even …