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Articles 91 - 120 of 122
Full-Text Articles in Engineering
Fiber Orientation Prediction And Strength Evaluation Of Composite Spur Gears Reinforced By Discontinuous Fiber, Nawrin Jahan
Fiber Orientation Prediction And Strength Evaluation Of Composite Spur Gears Reinforced By Discontinuous Fiber, Nawrin Jahan
Electronic Theses and Dissertations
Composite materials have been extensively used for their important role in attenuation of components design, low specific weight, high mechanical performance, and excellent corrosion resistance offer significant advantages over metallic materials. These superlative properties can be attained by tailoring different material in an appropriate combination of the reinforcing phase (carbon fiber, alumina, etc.) and matrix phase (polymer, ceramic, metals, etc.). Carbon fiber reinforced composites are mostly used on intricate stress sensitive structures like wings of aero plane or gear. Amount of fiber, fiber type, and size of the fiber and the orientation of reinforcing fibers directly influence the mechanical properties …
Characterization Of Mechanical Properties Of Gamma Irradiated Additively Manufactured Articles For In-Space Manufacturing, Behzad Rankouhi
Characterization Of Mechanical Properties Of Gamma Irradiated Additively Manufactured Articles For In-Space Manufacturing, Behzad Rankouhi
Electronic Theses and Dissertations
Recently, additive manufacturing (AM) has opened many doors to engineers across various industries, such as medical, bio-engineering, automotive and recently, aerospace. In an effort to contribute to the development of AM in aerospace industry, a series of experiments were designed to help understand the behavior of 3D printed parts and extend its capabilities and possible uses. The first chapter of this project will focus on understanding the mechanical behavior of additively manufactured articles. In this chapter, a comprehensive effort was undertaken to represent the strength of a 3D printed object as a function of layer thickness by investigating the correlation …
High Definition 3d Printing – Comparing Sla And Fdm Printing Technologies, Tyler Finnes
High Definition 3d Printing – Comparing Sla And Fdm Printing Technologies, Tyler Finnes
The Journal of Undergraduate Research
For consumer level additive manufacturing, there are currently two main methods to 3D print objects: Stereo lithography and Fused Deposition Modeling. Both processes add material, layer by layer, to create objects. Stereo lithography (SLA) uses a UV light source to selectively cure resin while Fused Deposition Modeling (FDM) extrudes semi-liquid plastic in a specific layout to create objects. As with most technologies, both styles of printing have advantages and disadvantages. The biggest advantage of SLA 3D printing is very high resolution. SLA 3D printing can produce objects with more than double the resolution of FDM printers. The mUVe 3D SLA …
Applications Of Ultrasonic Non-Destructive Testing In 3d Printing, Parker Lawley
Applications Of Ultrasonic Non-Destructive Testing In 3d Printing, Parker Lawley
The Journal of Undergraduate Research
To determine the capabilities of ultrasonic non-destructive testing methods in 3D printing, test specimens were designed to evaluate advantages and limitations in using ultrasoundC-scanning to determine 3D printing effectiveness. A Matlab program was written to process the data obtained from the UTwin software and ultrasound tank, as well as produce 3D models of the parts being tested. Thickness, types of features, and various printing methods were evaluated to determine how these characteristics vary in effectiveness of C-scan imaging. Results from the UTwin software C-scans were compared to the Matlab program’s imaging and three-dimensional modeling. After determining the capabilities of ultrasonic …
Integration Of A Pulsating Heat Pipe In A Flat Plate Heat Sink, Mitchell Hoesing
Integration Of A Pulsating Heat Pipe In A Flat Plate Heat Sink, Mitchell Hoesing
The Journal of Undergraduate Research
The ongoing development of faster and smaller electronic components has led to a need for new technologies to effectively dissipate waste thermal energy. The pulsating heat pipe (PHP) shows potential to meet this need, due to its high heat flux capacity, simplicity, and low cost. A flat plate PHP was integrated into an aluminum flat plate heat sink with a simulated electronic load. The PHP heat sink used water as the working fluid and had 20 parallel channels with dimensions 2 mm × 2 mm × 119 mm. Experiments were run under various operating conditions, and the thermal resistance of …
Vibrations Analysis On Tennis Racket String, Jenny Blackburne
Vibrations Analysis On Tennis Racket String, Jenny Blackburne
The Journal of Undergraduate Research
The purpose of this project was to investigate and analyse the vibration of a tennis racket string when a ball is hit. This was done using concepts of mechanical vibrations and modelled using Microsoft Excel. The displacement of the tennis string over time was graphed for two different positions on the racket and two different relative speeds of the tennis ball. It was found that the position of the tennis ball on the racket has very little effect on the displacement of the strings. If the ball or racket is moving faster when the ball is hit, then the displacement …
Assessment Of Corn Stover Torrefaction For On-Farm Biochar Production, Christina M. Gerometta
Assessment Of Corn Stover Torrefaction For On-Farm Biochar Production, Christina M. Gerometta
Electronic Theses and Dissertations
Torrefaction is a thermochemical pretreatment process that is typically achieved by slowly heating biomass (<50°C/min) within the temperature range of 200 – 300°C under an inert atmosphere. This process yields a storable solid product with enhanced fuel characteristics that are influenced by the ligno-cellulosic composition of the original feedstock and the imposed torrefaction conditions (time and temperature). This study is an assessment of corn stover properties that are relevant for designing an on-farm torrefaction system. The first portion of this study compared the thermal decomposition behaviors of corn stover fractions (leaf, stalk, cob) to the respective ligno-cellulosic composition using thermo-gravimetric analysis. It was found that the thermal decomposition pattern correlates to the structure and ratio of ligno-cellulosic polymers and provides design guidelines for an on-farm torrefaction system capable of handling large quantities of mixed fraction stover. The second part of this study investigated the effects of torrefaction time and temperature on the mass and energy yield of mixed fraction corn stover using a 46.3 L batch style reactor. It was found that longer reaction times and higher temperatures were required to obtain mass and energy yields similar to those found using lab-scale reactors and finely milled samples. Non-uniform torrefaction occurred between fractions due to chemical composition of each fraction and proximity to the heating elements.
Using Acoustic Emission Monitoring For Energy-Based Fatigue Life Prediction, Sepehr Nesaei
Using Acoustic Emission Monitoring For Energy-Based Fatigue Life Prediction, Sepehr Nesaei
Electronic Theses and Dissertations
The study of fatigue and fracture mechanics is crucial to the health monitoring and overall safety of aerospace and civil structures. The materials used to manufacture these industry parts have inherent anomalies that eventually grow under cyclic loadings during regular operation. The ASTM and/or military testing guidelines used to analyze and qualify structures and materials for use are costly and time consuming. Therefore, any additional methods or knowledge that can be used to reduce the number of tests will be useful to the industry to avoid unnecessary costs. Acoustic emission (AE) monitoring is currently used in many applications to assess …
Analysis Of Corn Stover Structural Properties For Mechanical Processing Applications, Taylor Suess
Analysis Of Corn Stover Structural Properties For Mechanical Processing Applications, Taylor Suess
The Journal of Undergraduate Research
The research objective of this study is to examine the behavior of chopped corn stover biomass as it undergoes a variety of mechanical loading conditions. Biomass materials, including corn stover, have unique properties that make it challenging to effectively and efficiently feed into thermochemical conversion systems that produce biofuels and bioproducts. These properties include large particle size, fibrous structure, and low density, to name a few. The most common difficulty in creating a system like this for corn stover is plugging within mechanical and pneumatic feeding systems. It is hypothesized that the material properties of fibrous corn stover contribute to …
Design, Fatigue, And Strength Analysis Of A Tie Rod Hydraulic Cylinder Bolt, Jacob Roemen, Donald Webber
Design, Fatigue, And Strength Analysis Of A Tie Rod Hydraulic Cylinder Bolt, Jacob Roemen, Donald Webber
The Journal of Undergraduate Research
This report illustrates strength and fatigue analysis completed on a tie rod hydraulic cylinder bolt from a Lion TX 2500 tie rod hydraulic cylinder. The goal was to: solve for total clamping force, damping force per bolt at 90% proof load strength, amount of force per bolt, find the required number of bolts to hold the hydraulic cylinder together, solve for bolt spacing requirements, estimate a safety factor based on proof load strength, nut shear strength, required nut thickness, the least number of threads that must be engaged, estimate R.R. Moore Bending Fatigue Strengths, estimate the maximum value of P …
Hydraulic Test Bench Circuit Construction, Testing, And Analysis, Shane Michelson, Mitch Mueller, Brett Schurman
Hydraulic Test Bench Circuit Construction, Testing, And Analysis, Shane Michelson, Mitch Mueller, Brett Schurman
The Journal of Undergraduate Research
Hydraulic power control systems are a common and important part of mechanical and agricultural systems. In hydraulic power system design, power, pressure, flow rates, and mechanism of circuitry are all important factors when analyzing any hydraulic system. Pumps, electric motors, reservoirs, working fluid properties, hydraulic circuitry, and a large variety of valves make up a functional hydraulic system. Applications for hydraulic systems vary widely from automotive, agricultural, mechanical etc. It is the engineers’ job to design a hydraulic system that will be functional, efficient, and safe.
Residual Stress Analysis Of Composite Cannon Barrel, Tyler Brockel, Ozan Ozdemir
Residual Stress Analysis Of Composite Cannon Barrel, Tyler Brockel, Ozan Ozdemir
The Journal of Undergraduate Research
The objective of this paper is to describe the process and results of a residual stress analysis done on a composite cannon barrel. A cross section of a full cannon barrel was cut off to be used in the analysis. The barrel cross section was composed of an inner steel layer that was wrapped in an outer composite layer. The residual stress analysis was done using x-ray diffraction (XRD). The XRD machine uses different types of x-ray tubes based on what material it is analyzing. For this reason, the first portion of the experiment dealt with finding the exact material …
Vibrational Analysis Of Soloflex Whole Body Vibration Platform, Zachary Croatt, Josh Robers
Vibrational Analysis Of Soloflex Whole Body Vibration Platform, Zachary Croatt, Josh Robers
The Journal of Undergraduate Research
A Soloflex Whole Body Vibration (WBV) Platform was tested for its frequency and magnitude of vibration at multiple settings on the supplied dial. An accelerometer was used to measure the vibrations on different points mapped across the platform. The motor attached to the board was also tested for its frequency using a high-speed camera. The amplitude measurements found from the accelerometer data was compared to the readings on the supplied control module to “calibrate” the platform for medical testing.
Vibrational Analysis Of An Electromechanical Toothbrush, Mark Wager
Vibrational Analysis Of An Electromechanical Toothbrush, Mark Wager
The Journal of Undergraduate Research
The effectiveness of an electromechanical toothbrush is based entirely on its ability to remove plaque through vibrations. This paper contests that the three-dimensional motion of more inexpensive models of electromechanical toothbrushes can be accurately modeled in one-dimension so as to predict the motion of future toothbrush designs using simply the material properties, motor specifications, and grip design. Vibrational modeling, mathematical modeling, and experimentation were used in the analysis to confirm the outcome of the study and the assumptions of the model.
Formula Sae Impact Attenuator Testing, Chad Abrahamson, Bill Bruns, Joseph Hammond, Josh Lutter
Formula Sae Impact Attenuator Testing, Chad Abrahamson, Bill Bruns, Joseph Hammond, Josh Lutter
The Journal of Undergraduate Research
The purpose of this paper is to validate the impact attenuator designed by SDSU Formula SAE team according to 2010 Formula SAE rules. The impact attenuator is made of Plascore PCGA-XR1-5.2-1/4-P-3003 aluminum honeycomb that is pre-crushed to 245 psi. The test was dynamically performed using a 661 lb mass dropped 8.3 ft onto the material sample at 23 ft/sec, and data was measured with an Olympus i-SPEED 3 high speed camera. The impact attenuator must have an average deceleration equal to or less than 20 G’s and a peak deceleration equal to or less than 40 G’s. Two specimens were …
Vibratory Feeder Bowl Analysis, Chris Green, Jeff Kreul
Vibratory Feeder Bowl Analysis, Chris Green, Jeff Kreul
The Journal of Undergraduate Research
Vibratory feeder bowls are used to feed small parts into various stations. At each station the parts will be rejected or accepted depending on the orientation of the part. This analysis was for Royal Plastics, Inc. who was looking to increase the production by increasing the part feed rate of one of their vibratory feeder bowls. As the parts are orientated they will be fed to a new station and often used in robotic systems that produce larger assembled products. The scope of this analysis is to produce a detailed analysis of the vibration system required to move parts through …
Wind Turbine Mounting Analysis, Chris Applen, Garet Miller, Ryan Jervik
Wind Turbine Mounting Analysis, Chris Applen, Garet Miller, Ryan Jervik
The Journal of Undergraduate Research
This paper analyzes the bolts and screws necessary to secure a certain wind turbine design to a silo. The analysis is divided into two major segments. First is the determination of maximum wind velocity and the resultant forces from the given wind conditions. The resultant force is determined from the dynamic pressure caused by the wind velocity and the surface area of the wind turbine blades. Second is carrying out the fatigue analysis to ensure the chosen bolts and screws will not fail. This is done through the use of a Goodman line diagram. In order for the fatigue design …
Modeling Of The Interior Electric Field In Photovoltaic Cells, Tara Jeatran
Modeling Of The Interior Electric Field In Photovoltaic Cells, Tara Jeatran
The Journal of Undergraduate Research
With the emergence of photovoltaic technologies, there is a strong technological demand for high-performance photovoltaic devices. One of the most promising device concepts developed at SDSU is organic-based photovoltaic cells. The performance of the PV cells is controlled by charge generation and charge separation, and charge transportation processes. Extraordinary control over the properties of the organic photovoltaic materials will be needed in order for this research to succeed. Therefore, the interior electric field and the macro electric properties of the system are the foundation behind these facts and are critical properties on their performance. In this paper, the fundamentals of …
Fatigue Analysis Of An Inline Skate Axel, Garrett Hansen, Mike Woizeschke
Fatigue Analysis Of An Inline Skate Axel, Garrett Hansen, Mike Woizeschke
The Journal of Undergraduate Research
In this paper, an inline skate axel is analyzed based on fatigue and economic principles for four different materials. The loading scenario on the axel of the inline skate is derived and broken down to a maximum shear stress that must be less than the maximum fatigue stress of the axel material. A fatigue analysis using Goodman line diagrams is applied to axels made of aluminum, titanium, nylon, and PVC. The material strengths are then compared to the loading requirements and determined whether they would be sufficient for an axel material. Finally, the prices are compared to verify the selection …
Analysis Of Wind Turbine Transverse Vibration, Matt Hein, Whitney Karpen
Analysis Of Wind Turbine Transverse Vibration, Matt Hein, Whitney Karpen
The Journal of Undergraduate Research
Large wind turbines have become an appealing choice for renewable electrical energy production throughout the world. The United States Midwest contains massive potential for wind energy development and is therefore being primed for large wind turbines to harvest this resource and bring it to market. Because of this, safety concerns have arisen in regard to their ability to withstand the harsh climate of the region. Analysis of the transverse vibration caused by severe weather will be preformed. A simplified model will allow for an analytical solution and displacement graphs produced with MATLAB code. This information will allow for an unbiased …
Vibration Analysis Of A Boat And Dock, Annicka Gunderson
Vibration Analysis Of A Boat And Dock, Annicka Gunderson
The Journal of Undergraduate Research
A structure is designed to withstand the maximum force that will be applied. In this case a boat dock is examined as a spring system. This exercise uses a typical design for a lake side boat dock, tires for buoys, and an average fishing boat. Vibration analysis can predict when the highest forces will occur. A solution can be found to graph the motion of the dock. In addition to the analytical solution, the MATLAB program is used to visualize the vibrations. With these tools the magnitude and timing of forces can be verified.
Theoretical Exploration Of Characteristics Of Up-Conversion Materials In Photovoltaics, Joel Bordewyk
Theoretical Exploration Of Characteristics Of Up-Conversion Materials In Photovoltaics, Joel Bordewyk
The Journal of Undergraduate Research
Up-conversion materials can be used to greatly enhance the productivity of photovoltaic nanotechnologies. These materials must convert photons from a low energy to a higher energy to fit within the acceptable range of the solar panel. Software is needed to compute the value of these energy levels and to find molecules that produce these values. It must first be determined if the software has these capabilities and if the results are trustworthy. Naphthalamide has been a molecule of interest and serves as a good starting point for these studies.
Dynamical Multi-Body Gyroscopic Motion Simulation, Andy Ries, Johnathan Deppe
Dynamical Multi-Body Gyroscopic Motion Simulation, Andy Ries, Johnathan Deppe
The Journal of Undergraduate Research
In this paper, the motion of a three-degree-of-freedom gyro scope is analyzed in three different force scenarios. The equations of motion for the gyroscope are derived by hand as well as derived by the dynamical analysis software, Autolev These equations are compared with each other to show the consistency between the two methods and the time savings of using software applications for analyzing complex multi-body dynamical systems. The Autolev™ program drastically reduced the workload for determining the motion equations and the program even compiled Matlab code that was used to produce numerical values to show the respective motion of each …
Economic Evaluation Of Integrating Biodiesel Production With A Dry Mill Ethanol Plant, Steven Bly
Economic Evaluation Of Integrating Biodiesel Production With A Dry Mill Ethanol Plant, Steven Bly
The Journal of Undergraduate Research
Biodiesei is produced by adding methyl ester products to diesel fuel. Base catalyzed transesterification of oil with methanol is the primary process used today. Current dry mill ethanol production facilities allow the com oil to pass through the process where it becomes part of the dried distiller's grain with solubles (DDGS), a lower valued feed co-product. This study evaluated the economic feasibility of integrating a biodiesel production facility with existing and/or new dry mill ethanol plants. The following methods for com oil separation were considered; hexane extraction of com oil from the dried distiller's grain stream, initial germ separation and …
Virtual Prototype Of Shuttle Bay Door, Nick Harrington, Raphael Schulz, Pierre Chapron
Virtual Prototype Of Shuttle Bay Door, Nick Harrington, Raphael Schulz, Pierre Chapron
The Journal of Undergraduate Research
This study analyzed the motion of the Space Shuttle free floating in space after one of its bay doors is opened and closed. Kane's method and Autolev motion simulation software were used to carry out simulation and analysis. The Space Shuttle has two large bay doors that open simultaneously, but for our study we analyzed a hypothetical situation, in which only one door functioned properly, in order to achieve amplified results. To model this system we used a rigid body to resemble the Shuttle and an attached rotating flap to resemble the door. Since the Shuttle is free floating in …
Comparison Of Theoretical And Experimental Results Pertaining To R-Curves In Low And High Ductility Solids, Rabindra Nath Dash
Comparison Of Theoretical And Experimental Results Pertaining To R-Curves In Low And High Ductility Solids, Rabindra Nath Dash
Electronic Theses and Dissertations
Existing linear elastic fracture mechanics and J-integral analyses are well suited for safety assessments of high-strength, low-toughness materials. These analyses apply only to the onset of crack growth, which is usually tantamount to crack instability and structural failure in that class of materials. However, this is not the case for the low-strength, high-toughness materials in which crack instability may be preceeded [sic] by extensive stable crack growth under rising loads. Here, a substantial margin of safety may exist even when the onset of crack growth is imminent. This thesis describes research leading to a ductile fracture-mechanics methodology designed to treat …
Torsional Vibrations Of A Composite Elastic/Viscoelastic Cylindrical Shaft, Deepak Kumar Mullick
Torsional Vibrations Of A Composite Elastic/Viscoelastic Cylindrical Shaft, Deepak Kumar Mullick
Electronic Theses and Dissertations
The primary objective of this research is to analyze the torsional vibrations of a composite bar, and the parameters associated with the vibrations. The ultimate goal in this study of vibrations is to determine their effect on the performance and safety of the system under consideration.
Experimental Study On Viscoelastic Properties And Fracture Characteristics In Polymers, Debaranjan Mohanty
Experimental Study On Viscoelastic Properties And Fracture Characteristics In Polymers, Debaranjan Mohanty
Electronic Theses and Dissertations
The research reported in this thesis is undertaken with the following objectives:
1. To determine the viscoelastic properties of polymers on creep test under constant load;
2. To determine the internal friction (loss factor) of polymers under periodic loading condition;
3. To determine the delayed time or life time on fracture of the polymer under constant loading ; and
4. To verify the relationship, theoretically predicted, between the time to fracture and the material characteristics of the polymer with experimental observations.
Experimental Investigation Of Shock Boundary Layer Interaction For Two-Dimensional And Axisymmetric Flow, A. Shawki Zahran
Experimental Investigation Of Shock Boundary Layer Interaction For Two-Dimensional And Axisymmetric Flow, A. Shawki Zahran
Electronic Theses and Dissertations
A supersonic wind-tunnel has been constructed using an 8 inch by 10 inch single stage jet vacuum ejector with a capacity of handling 0.4 lb/sec air at 4 inches Hg absolute suction pressure. A Toepler Schlieren system with 10-inch diameter parabolic mirrors has been set up for flow pattern visualization. The same apparatus was developed to obtain multi-colored views of the flow pattern. That was accomplished by placing an equilateral prism in front of the light source located at the focal plane of the first parabolic mirror. A spectrum was thus produced at the focal plane of the second parabolic …
Stress Analysis By Photoelastic Methods, Herald K. Palmer
Stress Analysis By Photoelastic Methods, Herald K. Palmer
Electronic Theses and Dissertations
The object of this article is to point out how the principles of photo elasticity may be used as a basis for the analysis of stresses in machine parts. It is also to review the methods and demonstrate the procedure for the determination of the characteristics and values of stresses in the models of the parts studied.