Mechanical Engineering Commons^™

Mapping Problem And Requirements To Solution: Document Analysis Of Senior Design Projects, Shraddha Joshi

All Theses

Formulating and solving engineering problems and designing solutions that meet the established requirements are important skills that graduating engineering students need to possess. However, there are noticeable gaps in the literature with respect to understanding how the formulation of design problems and establishment of requirements affect the final design solution. This thesis is an initial attempt to understand the influence of level of detail of problem statement and requirements on the level of detail of final solution. In doing so, a document analysis of final reports from senior design class collected over a period of ten years from 1999 to …

Analysis Of Alternative Manufacturing Processes For Lightweight Biw Designs, Using Analytical Hierarchy Process, Srinath Vijayakumar

All Theses

The main objective of the analysis was to investigate the forming of Body in White (BIW) panels using alternative processes most suitable for replacing the conventional press working process in order to achieve a reduction in the total mass of the vehicle body structure. The selection of the alternatives was guided by multi criteria decision making tool, the Analytic Hierarchy Process (AHP). Here the alternatives were selected based on their relative importance to the different manufacturing attributes considered. The selected processes were applied to the manufacturing of different parts of BIW indicated in the BOM along with suggestion of the …

Adapted Recumbent Bike, Kurtis Mundell, Dane Tiemeier, Laura Yakuma, Darius Yu

Mechanical Engineering

The adapted recumbent project was to redesign a disabled veteran’s recumbent bicycle. The main areas of concern were the crank pedal, chain tension, braking and steering system, and ergonomics. Since the customer is an avid biker, this bike will be used often, so the design is based on the ease of repair and replacement. The crank system was redesigned to a lightweight, adjustable part with chain clearance and high strength. The chain tension was improved by replacing the existing single idler wheel/chain tube system with a dual idler wheel system. The dual idler has a titanium sprocket in one of …

A Study Of The Statistics Of The Air/Water Interfacial Temperature Field During Mixed Convection Heat Transfer, Jie Kou

All Dissertations

Heat transfer across an air/water interface is of particular importance to limnology, oceanography and some industrial applications. The relationship between the statistics of the air/water interfacial temperature field and the interfacial heat flux is poorly understood, particularly for the mixed convection condition, which is a common heat transfer mechanism for small inland lakes. The few studies that have been conducted under mixed convection conditions have been limited to an uncontrolled surfactant condition (tap water). Therefore, in this dissertation research two sets of experiments for wind speeds from 0 to 4 m/s were conducted: controlled surfactant contaminated conditions (with oleyl alcohol) …

Artificial Skin Tactile Sensor For Prosthetic And Robotic Applications, Ross James Miller

Master's Theses

To solve the problem of limited tactile sensing in humanoid robotics as well as provide for future planned mechanical prostheses, an innovative tactile sensor system was created and embedded into two realistic-looking artificial skin gloves. These artificial skin tactile sensors used small piezoelectric ceramic disks to measure applied force at multiple points on each glove. The gloves were created using silicone rubber to simulate both the texture and look of human skin, while maintaining both flexibility and durability. The sensor outputs were buffered by high-impedance voltage-following operational amplifiers, and then read sequentially using a multiplexing scheme by a microcontroller. Sensor …

Energetics And Kinetics Of Dislocation Initiation In The Stressed Volume At Small Scales, Tianlei Li

Doctoral Dissertations

Instrumented nanoindentation techniques have been widely used in characterizing mechanical behavior of materials in small length scales. For defect-free single crystals under nanoindentation, the onset of elastic-plastic transition is often shown by a sudden displacement burst in the measured load-displacement curve. It is believed to result from the homogeneous dislocation nucleation because the maximum shear stress at the pop-in load approaches the theoretical strength of the material and because statistical measurements agree with a thermally activated process of homogeneous dislocation nucleation. For single crystals with defects, the pop-in is believed to result from the sudden motion of pre-existing dislocations or …

Fabrication Of Multi-Material Structures Using Ultrasonic Consolidation And Laser-Engineered Net Shaping, John Olorunshola Obielodan

All Graduate Theses and Dissertations

This research explores the use of two additive manufacturing processes for the fabrication of multi-material structures. Ultrasonic consolidation (UC) and laser- engineered net shaping (LENS) processes were used for parallel systematic investigations of the process parameters and methodologies for the development of multi-material structures.

The UC process uses ultrasonic energy at low temperature to bond metallic foils. A wide range of metallic materials including nickel; titanium; copper; molybdenum; tantalum; MetPreg®; silver; stainless steel; and aluminum alloys 1100, 3003, and 6061 were bonded in different combinations. Material domains are inherently discrete in ultrasonically consolidated structures. The mechanical properties of some of …

Integration Of Ultrasonic Consolidation And Direct-Write To Fabricate An Embedded Electrical System Within A Metallic Enclosure, Ludwing A. Hernandez

All Graduate Theses and Dissertations

A research project was undertaken to integrate Ultrasonic Consolitation (UC) and Direct-Write (DW) technologies into a single apparatus to fabricate embedded electrical systems within an ultrasonically consolidated metallic enclosure. Process and design guidelines were developed after performing fundamental research on the operational capabilities of the implemented system. In order to develop such guidelines, numerous tests were performed on both UC and DW. The results from those tests, as well as the design and process guidelines for the fabrication of an embedded touch switch, can be used as a base for future research and experimentation on the UC-DW apparatus. The successful …

A Study Of The Effect Of Vibration On Railroad Bearing Temperature, Bertha Alicia Gonzalez

Theses and Dissertations - UTB/UTPA

An on-track collaborative field test and laboratory experiments were conducted in order to determine the relationship between abrupt rises in surface temperature of a railroad bearing and vibration signatures captured during the experiments. The collaborative field test was conducted in order to investigate the root cause for this abrupt temperature change known as bearing temperature trending. The research presented in this thesis will show that temperature trending is correlated to an increase in the magnitude of vibration within the bearing and the fundamental frequencies that are generated by the internal components of a rotating bearing assembly. Distinct vibration mechanisms are …

Mobility Aid: A Dual Purpose Walker And Scooter, Zack Blois, Robia Choi, Kristin Dills

Mechanical Engineering

The Mobility Aid project was proposed by Theresa Mortilla and Idee Shapiro. The goal of the project was to design and build a device that can quickly and easily transform between a mobility walker and an electric scooter to allow for more freedom of mobility. The inspiration for this project arose from the fact that Theresa suffers from multiple sclerosis in her legs and can only walk for about thirty minutes at a time until she gets too fatigued and must sit down and rest. This device would provide her with the ability to continue moving while giving her legs …

Cal Poly Rose Float Electric Vehicle, Jennifer Slone, Jason Sherrett, Dionysios Pettas, Timothy Baldwin

Mechanical Engineering

(1) Background:

The Cal Poly Rose Float is currently powered by a pair of V-8 internal combustion engines. This is the second project in a three phase effort to replace the existing drive engine with an electric motor powered by a DC bus. The main goal of this phase of the project is to get the motor selected in phase one spinning.

(2) Results:

Originally, the project involved programming a microcontroller to achieve motor control. The decision was made, early on, to approach this task in a different manner due to the team’s minimal background in programming and mechatronics. The …

Water Well Drilling Rig Final Project Report, Alexander (Alex) Wargnier, Thad Jablonski, Coel Schumacher

Mechanical Engineering

In this report, the improvements of a previously produced cable tool drilling rig are described. The purpose of the rig is to drill water wells for use in Africa in order to provide safe drinking water to many in need. An affordable, effective, and controllable rig is the design goal for this project. With the San Luis Obispo Rotary Club sponsoring the project the design team of WHole Engineering have made necessary design choices to manufacture the product. Actions performed include background research of existing drilling technologies, analysis of top concepts for the controlling mechanism, and selection for the final …

Foam Wars Ii, Sumant Advani, Sivadas Menon, Casey Pieplow

Mechanical Engineering

The team producing Foam Wars II consists of three Mechanical Engineering students and five Kinesiology students (three the first two quarters and two the last quarter) at California Polytechnic State University, San Luis Obispo. The project is the second iteration of Foam Wars as a senior project at Cal Poly, sponsored by Dr. Kevin Taylor under the National Science Foundation grant. Persons with disabilities often feel limited when it comes to recreational activities and Foam Wars would provide them with an outlet to interact and engage themselves in a group setting. The game consists of various wheelchair attachments that would …

The Quadricycle Hand And Foot Cycle, Marissa Chin, Parker Drennan, Spencer Nelson, Kevin Reidy

Mechanical Engineering

This report documents the design process from concept generation to manufacturing for a hand and foot powered cycle named the Quadricycle. The Quadricycle project is a joint effort at California Polytechnic State University in San Luis Obispo between the Mechanical Engineering and Kinesiology Departments. The project objectives are to design a portable cycle that can be powered by hands and feet simultaneously in order to provide recreation and rehabilitation for a person with a disability. This project is funded under a grant by the National Science Foundation (NSF).

Universal Play Frame Vi, Justin Bazant, Cullen Crackel, Anthony Franceschi

Mechanical Engineering

This design report details the design process utilized by Adaptive Exercise Designs (AED) in creating the sixth design of the Universal Play Frame (UPF). The UPF is an adaptive frame which supports a variety of devices that allows athletes in wheelchairs with limited range of motion to participate in physical activity. The past five frame designs do not meet the needs of the Friday Club due to complications with function and time constraints. To ensure all of Fridays Club's needs were met, the problem was better defined by converting the customer requirements into engineering specifications. The design process our team …

Piedras Blancas Clock Works, Andrew James, Andrew Jupin, Matt Weber

Mechanical Engineering

In 1875, the Piedras Blancas Lighthouse was built to warn ships sailing the California coast of the hazards of the rocky shore. In 1949 a fierce storm damaged the top portion of the lighthouse and the eight ton cast iron and brass assembly had to be replaced by a much lighter piece that still served the purpose of warning oncoming vessels. The former top portion came to rest in downtown Cambria and is still there today, enclosed in a glass room to be observed by visitors and townspeople. Today, the Piedras Blancas Light station is cared for by the Bureau …

Development And Characterization Of Shock Tubes For Laboratory Scale Blast Wave Simulation, Aaron D. Holmberg

Engineering Mechanics Dissertations & Theses

The prevalence of traumatic brain injury (TBI) in American soldiers exposed to a blast wave has created an urgent need to better understand the effects of blast wave insult to the head. Developing techniques that can experimentally simulate well controlled blast waves in a laboratory environment is a critical component of the research efforts towards this goal. For this work, a 4-in. cylindrical uniform shock tube and a nonuniform shock tube combining a 4-in. cylindrical gas driver with a 9-in. square driven section have been developed. The hosting laboratory, gas handling system, multichannel data acquisition systems, and the related network …

Computational Analysis For Improved Design Of An Sae Baja Frame Structure, Nagurbabu Noorbhasha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Baja SAE is an intercollegiate competition to design, fabricate, and race a small, single passenger, off-road vehicle powered by a 10 HP Briggs & Stratton 4-Stroke gasoline engine. All Baja SAE vehicles for the competition are powered by a small engine, thus large part of vehicle performance depends on the acceleration and maneuverability of the vehicle which is proportional to the weight of the chassis and rollcage. As weight is critical to achieve the greater performance of the vehicle, a balance must be found between the strength and weight of the rollcage to ensure the safety of the driver.

The …

Effect Of Moisture Absorption On The Sinter Quality Of Central Solenoid (Cs) Coil Pack, Zeshaan Sher Mohammed

Masters Theses

Fusion energy has been said to be the solution to all the world’s energy problems. The International Thermonuclear Experimental Reactor (ITER) is the flagship project to demonstrate the feasibility of fusion energy. The Central Solenoid (CS), an important component of the reactor, is needed to induce plasma current, initiate, ramp-up, ramp-down, and sustain plasma in a very controlled manner. In order to achieve this, the CS coil packs must be manufactured under controlled conditions. The CS conductor is an advanced cable-in-conduit Nb3Sn superconductor. The CS cable will be made in long continuous sections but with thousands of meter of cable …

Experimental And Computational Analysis Of An Energy Storage Composite Ankle Foot Orthosis, Michelle C. Hawkins

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ankle Foot Orthotics (AFOs) are used by individuals presenting with Charcot-Marie-Tooth (CMT) to assist with improving gait. Mitch Warner, CPO, has developed a composite AFO made from woven carbon-Kevlar and carbon fiber lamina. The overall goals of the research are to characterize the HELIOS brace and to determine its effect on the gait of CMT subjects. Human motion analysis, experimental mechanical testing, and Finite Element Analysis (FEA) are used to gain a better understanding of how the materials and geometric design of the HELIOS AFO contribute to gait.

Human motion experiments are performed to determine the relationship between ground reaction …