Mechanical Engineering Commons^™

Enhanced Reducibility And Conductivity Of Na/K-Doped Srti0.8Nb0.2O3, Guoliang Xiao, Sirikanda Nuansaeng, Lei Zhang, Suwit Suthirakun, Andreas Heyden, Hans-Conrad Zur Loye, Fanglin Chen

Faculty Publications

Donor and acceptor co-doped SrTiO₃ materials have shown interesting features in their conductivity and reducibility. In this work, 10 mol% Na⁺ or K⁺ as acceptor dopants have been introduced into the A-site of donor-doped strontium titanate, SrTi_0.8Nb_0.2O₃, and the doping impact on their properties has been studied. By doping with Na or K, the sinterability of SrTi_0.8Nb_0.2O₃ in reducing atmospheres has been improved. Na_0.1Sr_0.9Ti_0.8Nb_0.2O₃ and K_0.1Sr_0.9Ti_0.8Nb_0.2O₃ show metallic …

The Mechanics Of Intracranial Loading During Blast And Blunt Impacts: Experimental And Numerical Studies, Veera Selvan Kuppuswamy

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Head injuries in an explosion occur as a result of a sudden pressure changes (e.g. shock-blast) in the atmosphere (primary injury), high velocity impacts of debris (secondary injury) and people being thrown against the solid objects (tertiary injury) in the field. In this thesis, experimental and numerical approaches are used to delineate the intracranial loading mechanics of both primary (blast) and tertiary injuries (blunt).

The blast induced head injuries are simulated using a fluid-filled cylinder. This simplified model represents the head-brain complex and the model is subjected to a blast with the Friedlander waveform type of loading. We measured the …

Propagation Of Thermo-Mechanical Waves In Deforming Nonlinear Viscoelastic Bodies, Lili Zhang

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

This work studies the propagation of thermo-mechanical disturbances in bodies made of viscoelastic materials that might already be loaded such that they are undergoing large inhomogeneous time varying deformations. In the process of this study we develop the general equations governing the thermo-mechanical motion of such disturbances and ones for internally constrained systems, provide the general structure of the solution, match the solution to existing results for the special case of time harmonic plane waves in elastic bodies and in viscoelastic bodies under constant homogenous loading, and consider some special applications.

The results of this work should have applications in …

An Applied Numerical Simulation Of Entrained-Flow Coal Gasification With Improved Sub-Models, Xijia Lu

LSU New Orleans Theses and Dissertations

The United States holds the world's largest estimated reserves of coal and is also a net exporter of it. Coal gasification provides a cleaner way to utilize coal than directly burning it. Gasification is an incomplete oxidation process that converts various carbon-based feedstocks into clean synthetic gas (syngas), which can be used to produce electricity and mechanical power with significantly reduced emissions. Syngas can also be used as feedstock for making chemicals and various materials.

A Computational Fluid Dynamics (CFD) scheme has been used to simulate the gasification process for many years. However, many sub-models still need to be developed …

Relaxation Of Shear-Induced Precursors In Isotactic Polypropylene And Random Propylene–Ethylene Copolymers, Benjamin Schammé

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Flow induced crystallization (FIC) has a large impact on kinetics and morphology of semicrystalline polymers, and can therefore drastically change final properties such as dimensional and thermal stability, modulus and strength. Processing of polymers usually involves flow, so it is important to understand the mechanism of FIC. It is known that oriented precursors formed during flow are the key to FIC but they are not yet well understood. In this study, flow induced precursors are investigated by examining their relaxation, and the effect of comonomer is probed.

Using a commercial isotactic polypropylene and random propylene-ethylene copolymers, a fiber pull-out technique …

Measurement And Description Of Dynamics Required For In Vivo Surgical Robotics Via Kinematic Methods, Jacob G. Greenburg

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

With the goal of improved recovery times and reduced trauma to the patient there has been a substantial shift in the medical community’s demand for minimally invasive surgical (MIS) techniques. With the standardization of MIS becoming more commonplace in the medical field there are still many improvements that are desired. Traditional, manual methods of these surgeries require multiple incisions on the abdomen for the tools and instruments to be inserted. The more recent demand has been to localize the incisions into what is being referred to as a Laparoendoscopic Single-Site (LESS) surgery. Furthermore, the manual instruments that are commonly used …

Interface Properties Of Bio-Based Composites Of Polylactic Acid And Bamboo Fibers, Quentin Viel

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Environmental impact plays an ever-increasing role in the industrial production of materials, and because of its importance, the scientific community is examining a wide variety of new materials that are more environmentally friendly. Bioplastics are characterized by the fact that the usual petrochemical resins (polypropylene, polyethylene etc.) are replaced by bio-sourced resins and the reinforcements (glass fibers, carbon fibers etc.) are replaced by natural fibers (bamboo, flax, cotton, etc.). Polylactic acid (PLA) is a biodegradable polymer that is increasingly used in biomedical applications and in packaging. Additionally, bamboo is a promising source of fibers that could be used as reinforcement. …

Development Of A Controllable Polymer System Using Interpenetrating Networks, Emilie Bobo

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

My research partners and I have studied the possibility of building a material system with controllable properties using two interpenetrating polymer networks (IPNs). This study is part of a project to build a rapid prototyping system that allows for the printing of objects with predefined spatial distribution of properties, with the goal that property distributions are controlled though interactions at the molecular level.

One can change the properties of an IPN by adjusting the ratio of interpenetrating networks present in a given cured mixture. This is similar to how one obtains different shades of the color green by gradually changing …

Design Of A Compliant Underactuated Robotic Finger With Coordinated Stiffness, Etienne Dessauw

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The concept of underactuation has been previously developed in the robotic field for grasping applications. For these anthropomorphic grippers, the minimization of the number of input signals, or in other words underactuation, is the most expected characteristic. This method has become very popular in recent decades. Indeed, by minimizing the number of input signals, it minimizes the complexity of the system’s control and at the same time avoids increased weight and cost. The inconvenience of such a technique is that the design of this type of system remains a difficult task if the behavior of the underactuated set of joints …

Reliability-Based Design Optimization Of Concrete Flexural Members Reinforced With Ductile Frp Bars, Bashar Behnam, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

In recent years, ductile hybrid FRP (DHFRP) bars have been developed for use as tensile reinforcement. However, initial material costs regain high, and it is difficult to simultaneously meet strength, stiffness, ductility, and reliability demands. In this study, a reliability-based design optimization (RBDO) is conducted to determine minimum cost DHFRP bar configurations while enforcing essential constraints. Applications for bridge decks and building beams are considered, with 2, 3, and 4-material bars. It was found that optimal bar configuration has little variation for the different applications, and that overall optimized bar cost decreased as the number of bar materials increased.

Multilink Suspension & Steering System For Cal Poly Formula Electric, Tristan French, Alissa Roland, Maximilian Sluiter

Mechanical Engineering

The purpose of this project was to design a suspension that would improve the performance of the Cal Poly SAE Formula Electric car around a racing track Performance would be quantified through skidpad, slalom, and straight-line acceleration tests as well as autocross lap times. The approach to meeting the objective was to increase the steady-state lateral acceleration and quicken the transient response while maintaining predictable handling so that the driver could extract maximum performance from the car.

The car uses round-section (motorcycle) tires at a large negative camber angle because the lateral force generated by a pair of negatively-cambered tires …

Evs Sports Knee Brace Testing Machinefinal Design Report, Silvia Aguilar, Nick Mattison, Chris Mccarthy

Mechanical Engineering

The purpose of this document is to report on the development of a test machine for EVS’ Web and Axis knee braces. Between September 2012 and June 2013, Team CSN, comprising of Nick Mattison, Silvia Aguilar, and Chris McCarthy, have methodically planned, designed, built, and tested this machine. The overarching goal of this unique machine is to address the need for both hyperextension and fatigue testing. From here on out this report dives into details of the machine with an Appendix C reporting testing results of said knee braces.

Drape Forming Machine, Adam Johnson, Will Schlosser, Brian Miller

Mechanical Engineering

The goal of this project was to build a prototype machine that formed multiple sheets of debulked pre-preg OOA carbon fiber into a 2-foot long trapezoidal shape. The machine was required to do this process semi-automatically.

Rapid Decompression Containment System, Evan Domingue, Michelle Rudney, Daniel Trees

Mechanical Engineering

Cal Poly students; Evan Domingue, Michelle Rudney and Daniel Trees; are working with General Atomics Aeronautical Systems, Inc. (GA, ASI) and engineer John Wilcox to complete a senior project. The senior project is focused on finding a solution to meet the requirement set forth in MIL-HDBK 1791 4.2.5.2 for rapid decompression which requires cargo items to be designed with pressure relief devices or to be configured for air shipment as to prevent any part from becoming a projectile in the event of catastrophic loss of aircraft cabin pressure. The goal of this project is to design a safe, cost-effective, and …

Adaptive Golf Device, Nick Baker, Katie Delaurentis, Grant Martens, Liz Allison

Mechanical Engineering

Our primary objective was to design a golf device that enables its user, who has limited leg movement and control, to be able to produce a balanced golf swing. Ultimately, the device maximizes the golfer's independence, and increases the accuracy of and power behind each shot. Specifically, the device was designed around the needs and requirements of Dr. Joshua Pate, Professor of Adapted Recreation at James Madison University. Dr. Pate has cerebral palsy limiting his lower body mobility and making it difficult for him to produce a balanced golf swing.

Loaded Shift Tester Sram, Nick Cox, Sam Shaffer, Michael Polka

Mechanical Engineering

This report details the design, manufacturing, and testing of a loaded shift tester for the SRAM Bicycle Corporation. The machine is used to perform developmental and qualification tests on various bicycle drivetrain components. Using SolidWorks, the design team created a solid model of the machine on the computer, then ordered and manufactured the parts required to build it. The machine was tested to ensure that all the parts worked together, and was finally delivered to SRAM when it was deemed ready.

Bicycle Wheel Test Machine, Dylan Harper, Kevin Hom, Ross Williams

Mechanical Engineering

In recent years, the cycling industry has witnessed huge advancements in bicycle components and materials. The age old goals of speed and low weight are still present today, but the pursuit of these goals may be reducing the structural stability of various components integral to wheel performance, including the wheel hub bearings. These bearings are invaluable to bicycles but little is known about how the forces and loads applied to a bicycle affect the performance of these bearings. Broken axles and hubs are indicators of significant stresses within the hub, but little is known about how the resulting deformation affects …

Hoist To Transfer Athletes From Wheelchair Into A Kayak, Jennifer Batryn, Javier Mendez, Kyle Mooney

Mechanical Engineering

No abstract provided.

Exploration Station Kidshake Table, Jeremy Duhe, Philip Hopkins, Matt Ostiguy, Samantha Weiner

Mechanical Engineering

The KIDShake Table is an all mechanical earthquake shake table sponsored by the Exploration Station Children's Museum of Grover Beach. This interactive exhibit has two working mechanisms, a hand crank and pull rope, that provide two axis movement for knocking down block structures. This table was built and designed for a target age of 10 years.

Dedion Axle Senior Project, Nick Schraan, Mark Shushnar, William Swenson, Ramy Tall

Mechanical Engineering

The sponsor, EV Grid Inc. is a company looking to the future with the development of a vehicle to grid infrastructure. The vehicle in development is a Ford E-250 Van which had been converted to electric drive with a front motor, rear drive layout. The sponsor wanted to move the electric motor to the rear and develop an axle to support this change. By eliminating the driveshaft, a more efficient use of battery space could be utilized. The goal of this project is to design and fabricate a prototype deDion rear axle which incorporates a system of drive components that …

Rebounder Fatigue Test Machine, Caroline Reeves, Will Robertson, Ethan Flory

Mechanical Engineering

JumpSport, a company that designs and sells trampolines and trampoline accessories, has sponsored this senior project team to design, build, and test a trampoline fatigue test machine. The machine must simulate a person jumping on the trampoline to test the life of JumpSport’s fitness trampolines and kids’ trampolines. Partway through the design process, the objectives were altered and this senior project team was tasked with merging with another Cal Poly senior project group to create an all-inclusive test machine to accommodate both full-trampoline testing and individual bungee cord testing.

The final design is centered on a slider crank linkage driven …

Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform, Jeffrey J. Maniglia Jr.

Master's Theses

This paper describes the changes made from Cal Poly’s initial railgun system, the Mk. 1 railgun, to the Mk. 1.1 system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency losses. A Mk. 2 system is developed and built around donated hardware from the Naval Postgraduate School. The Mk. 2 system strove to implement an efficient, augmented, electromagnetic …

Design And Fundamental Understanding Of Minimum Quantity Lubrication (Mql) Assisted Grinding Using Advanced Nanolubricants, Parash Kalita

Graduate Theses and Dissertations

Abrasive grinding is widely used across manufacturing industry for finishing parts and components requiring smooth superficial textures and precise dimensional tolerances and accuracy. Unlike any other machining operations, the complex thermo-mechanical processes during grinding produce excessive friction-induced energy consumption, heat, and intense contact seizures. Lubrication and cooling from grinding fluids is crucial in minimizing the deleterious effects of friction and heat to maximize the output part quality and process efficiency. The conventional flood grinding approach of an uneconomical application of large quantities of chemically active fluids has been found ineffective to provide sufficient lubrication and produces waste streams and pollutants …

Design Of Experimental Methods To Test The Performance Of Pads And Helmets Under Blast Loading Conditions, Kurtis Palu

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Improvised explosive devices (IEDs) have become a primary weapon in conflicts against US and allied forces. Improvements in body armor and medicine have increased the survivability of such events. These factors have caused an increase in traumatic brain injury (TBI) and mild traumatic brain injury (mTBI) induced by primary blast waves. Injury mechanisms caused from primary blast waves are not clearly understood or defined. How primary blast waves interact with materials or between narrow gaps found between helmet pads is not known. Two novel test fixtures were developed to provide a basic understanding of these two issues.

The first fixture …

Transient Small Wind Turbine Tower Structural Analysis With Coupled Rotor Dynamic Interaction, George R. Katsanis

Master's Theses

Structural dynamics is at the center of wind turbine tower design - excessive vibrations can be caused by a wide range of environmental and mechanical sources and can lead to reduced component life due to fatigue, noise, and impaired public perception of system integrity. Furthermore, periodic turbulent wind conditions can cause system resonance resulting in significantly increased structural loads. Structural vibration issues may become exacerbated in small wind applications where the analytical and experimental resources for system verification and optimization are scarce. This study combines several structural analysis techniques and packages them into a novel and integrated form that can …

Vulnerability Of Progressive Collapse In Reinforced Concrete Flat-Plate Buildings, Jinrong Liu

College of Engineering: Graduate Celebration Programs

• Progressive collapse is the spread of initial local failure, causing partial or
  even total collapse of a building.
• Flat plate structure is widely used for office and residential buildings.
• There is a large inventory of older flat plate building without continuous slab bottom reinforcement through columns.
• Limited knowledge exists regarding the risk of disproportionate collapse in
  older flat-plates under sudden column removal during abnormal events.
• Reliable mechanical model is needed for structural evaluation.

Computational Dynamics For The Flexible Multi-Body System, Yu Liu

Mechanical & Aerospace Engineering Theses & Dissertations

Research in computational dynamics has tremendously developed in the recent years because of the demand for analysis and simulation of various multi-body systems in the growing bio-medical, mechanical and aerospace industries. These multi-body systems are made of individual bodies that are interconnected via mechanical joints. Mathematically, these joints that connect the bodies can be described as constraint equations imposed upon the motions of the involved free bodies. This process will result in an equation of motion expressed in the form of a differential-algebraic equation (DAE). This is one of the main difficulties when dealing with the multi-body system because these …

Enhanced Nucleate Boiling On Horizontal Hydrophobic-Hydrophilic Carbon Nanotube Coatings, Xianming Dai, Xinyu Huang, Fanghao Yang, Xiaodong Li, Joshua Sightler, Yingchao Yang, Chen Li

Faculty Publications

Ideal hydrophobic-hydrophilic composite cavities are highly desired to enhance nucleate boiling. However, it is challenging and costly to fabricate these types of cavities by conventional micro/nano fabrication techniques. In this study, a type of hydrophobic-hydrophilic composite interfaces were synthesized from functionalized multiwall carbon nanotubes by introducing hydrophilic functional groups on the pristine multiwall carbon nanotubes. This type of carbon nanotube enabled hydrophobic-hydrophilic composite interfaces were systematically characterized. Ideal cavities created by the interfaces were experimentally demonstrated to be the primary reason to substantially enhance nucleate boiling

Mechanics Of Blast Loading On Post-Mortem Human And Surrogate Heads In The Study Of Traumatic Brain Injury (Tbi) Using Experimental And Computational Approaches, Shailesh Govind Ganpule

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Blast induced neurotrauma (BINT) has been designated as the “signature injury” to warfighters in the recent military conflicts. The occurrence of traumatic brain injury (TBI) in blasts is controversial in the medical and scientific communities because the manifesting symptoms occur without visible injuries. Whether the primary blast waves alone can cause mechanical insult that is comparable to existing traumatic brain injury thresholds is still an open question, and this work is aimed to address this issue.

In the first part of this dissertation, mechanics of primary blast loading on Realistic Explosive Dummy (RED) head with and without helmets is studied …

Analysis Of Alternative Ductile Fiber-Reinforced Polymer Reinforcing Bar Concepts, Bashar Behnam, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

Steel-reinforced concrete structural components are often associated with significant maintenance costs as a result of reinforcement corrosion. To mitigate this problem, fiber-reinforced polymer (FRP) bars have been used in place of traditional steel reinforcement for some applications. The non-ductile response of typical FRP bars is a concern, however. To overcome this problem, hybrid ductile FRP (HDFRP) bars have been developed for use in concrete flexural members with resulting ductility indices similar to sections reinforced with steel. In this study, five different HDFRP bar concepts are analyzed and compared in terms of ductility, stiffness, and relative cost. Of primary interest is …