Engineering Commons^™

Prediction Of In-Plane Stiffnesses And Thermomechanical Stresses In Cylindrical Composite Cross-Sections, Bryson M. Chan

Master's Theses

Accurate mechanical analysis of composite structures is necessary for the prediction of laminate behavior. Cylindrical composite tubes are a mainstay in many structural applications. The fundamental design of circular composite cross-sections necessitates the development of a comprehensive composite lamination theory. A new analytical method is developed to characterize the behavior of thin-walled composite cylindrical tubes using a modified plate theory. A generated numerical solver can predict properties such as axial stiffness, bending stiffness, layer stresses, and layer strains in composite tubes subjected to combined mechanical loading and thermal effects. The model accounts for the curvature by transforming and translating the …

Composite Pegboard, Asa J. Cusick, Luis Corrales, Joelle Hylton, Wyatt Pauley

Mechanical Engineering

Many of those with mobility limitations who are told they will need a wheelchair for the rest of their lives can actually begin to stand and walk again given the proper tools and support. The current design for a wheelchair seeking to support this process is overly complex, heavy, and exhibits some features that could potentially pose a serious health hazard to those using it. The scope of this project is to aid in the design of an adaptable composite wheelchair frame that can be both lightweight and strong, while still allowing for physical diversity of potential users. Through research …

Effects Of Bio-Composites In Corrugated Sandwich Panels Under Edgewise Compression Loading, Jalen Christopher Mano

Master's Theses

Present day composite sandwich panels provide incredible strength. Their largest problem, however, is early bonding failure between the core and the skin. This is due to the low bonding surface area of present cores like honeycomb. Corrugated structures could provide a remedy for this with their much larger bonding surface area. Corrugated structures have extreme mechanical properties deeming them particularly useful in aerospace and automotive applications. However, previous research has shown that the stiffness of carbon fiber causes debonding and drastic failure when used as both a core and a skin. Bio-composites have properties that could strengthen the corrugated sandwich …

Reinventing The Wheel, Esther K. Unti, Ahmed Z. Shorab, Patrick B. Kragen, Adam M. Menashe

Mechanical Engineering

Reinventing the Wheel selected tires and designed wheels for the 2018 Cal Poly, San Luis Obispo Formula SAE combustion vehicle. Available tire options were evaluated for steady-state and transient performance as well as vehicle integration. A single-piece composite wheel with hollow spokes was designed to meet stiffness, strength, and tolerance requirements. A detailed study of wheel loading and geometric structural efficiency was performed. Finite element analysis was used to iterate the geometry and laminate. A two-piece male mold was designed and machined to manufacture the wheel. Removable silicone inserts were used to create the hollow spokes.

Composite Suspension For A Mass Market Vehicle, Sarah M. Chapiama, Brian Auyeung, Jose Guerrero, Ethan Lau

Mechanical Engineering

Statement of Confidentiality: The complete senior project report was submitted to the project advisor and sponsor. The results of this project are of a confidential nature and will not be published at this time.

Manufacture Of Complex Geometry Component For Advanced Material Stiffness, David Russell Bydalek

Master's Theses

The manufacture, laminate design, and modeling of a part with complex geometry are explored. The ultimate goal of the research is to produce a model that accurately predicts part stiffness. This is validated with experimental results of composite parts, which refine material properties for use in a final prototype part model. The secondary goal of this project is to explore manufacturing methods for improved manufacturability of the complex part. The manufacturing portion of the thesis and feedback into material model has incorporated a senior project team to perform research on manufacturing and create composite part to be used for experimental …

Development Of 3d Compression Molded Composite Primary Structure, Sean D. Tischler, Jacob H. Goldstein, Alea A. Perez

Mechanical Engineering

The work accomplished by the Black Gold team improved upon the carbon fiber compression molding research and information available on the Cal Poly San Luis Obispo campus. The team used the rear suspension rocker arm off a Ventana Alpino mountain bike as a design goal for this project. This research and body of work includes the methods used to design a compression molded part for complex part loading and shape. This extends to the process of choosing an appropriate layup process, in addition to benefits and drawbacks of the use of chopped fibers in compression molding. The research includes the …

Bear Minimum: Ultralight Composite Bear Canister, Rama B. Adajian, Adam C. Eisenbarth

Mechanical Engineering

The ultralight backpacking community needs a strong, easy to use, safe bear canister that is lighter than current market products for trekking in the backcountry. A full design of the lid for the bear canister is to be completed. This includes the locking mechanism to ensure it is bear proof, the interface between the lid and the canister, and the structure of the lid so it passes the strength and weight specifications. The lid, along with the already designed canister body, is to be manufactured with formal documentation. The lid will initially be tested separately and then with the canister …

Compression Molded Composite Component, Greg Hermansen, Larsson Johnson, Joanne Medrano, Kyle Hammell

Mechanical Engineering

The following final design report outlines the design and fabrication of a carbon fiber compression molded sunglasses case. It intends to guide the development of a future lab activity for a composites undergraduate course at Cal Poly – San Luis Obispo. The activity aims to support an educational investigation in "out-of-autoclave" composites manufacturing methods, such as compression molding, which offer some key benefits over autoclave molding. The methodology behind the creation of a conceptual design, an initial prototype, and a final product is laid out in detail below.

Ultra-Light Bear Canister, Naveen Beasley, Eli Rogers, Cory Wilson, Donald Wood

Mechanical Engineering

A bear canister is the primary tool used by outdoor enthusiasts to protect their food from bears while camping or backpacking. There are many effective products currently on the market, however many are not designed with reduced weight in mind. Hardcore backpackers want to have the lightest gear possible to ease the strain of carrying a large pack for sometimes weeks at a time.

Current bear canisters exist that utilize carbon fiber for weight reduction, however they rely on stock carbon tubes and lack engineering analysis, and no competitor has a fully composite bear canister available. Our sponsor, Nick Hellewell, …

Formula Sae Hybrid Carbon Fiber Monocoque / Steel Tube Frame Chassis, Matthew Hagan, John Rappolt, John Waldrop

Mechanical Engineering

The Cal Poly Formula SAE Team created this project in order to design and fabricate a high-performance chassis which would be competitive at 2013 FSAE Lincoln, and to document the process so that future teams could more easily create a chassis. One of the main goals was to reduce weight from the 143- lb 2012 chassis subsystem. A weight of 95 lb was achieved, with 82 lb in the chassis structure itself and a predicted torsional stiffness of 1700 lb*ft/deg. Composite materials design and manufacturing techniques were developed during the project. Design, testing, and manufacturing processes are detailed, and results …

Biaxial & Twist Testing Of Composite Carbon-Fiber Sandwich Panels For Automotive Racing Vehicles, Erik Eckberg

Materials Engineering

Composite sandwich panels were constructed with 4-ply plain weave carbon-fiber/epoxy face sheets in the 0^o/45^o/0^o/45^o orientation and 1/8^th inch Nomex honeycomb core. The panels were cut into 5-inch square test plates for mechanical testing. All testing was done on a fixture designed and fabricated by Pratt & Miller Engineering and installed on an Instron testing system at Cal Poly. The twist test was performed by supporting diagonal corners of the plate while simultaneously loading the opposite two corners at a crosshead rate of .06 in/min (ASTM 3044-94R11). Out of 10 panels tested, …

Human Powered Helicopter: Rotor Structure, Joseph Ram, Juan Carlos Olvera

Mechanical Engineering

The following report encompasses the Human Powered Helicopter Rotor Team’s conceptual models and ideas based on research and modeling analysis. The following gives an overview of material researched, concept generation, analyzation, manufacturing, and testing for a rotor structure to be installed in a Human Powered Helicopter.

An Investigation Of Damage Arrestment Devices On Carbon Fiber Sandwich Specimens Under Dynamic Loading, Gabriel Sabino Sanchez

Master's Theses

This research studies the effects of a damage arrestment device embedded between a carbon fiber facesheet and foam core to find whether there is an increase in the structural integrity of the sandwich composites. Experimental and theoretical finite element analyses are implemented for two different composite sandwich geometries; plates and beams. Each structure consisted of the same loading criteria and was restricted to the same vibration fixture during the experiment. An accelerometer was placed on the composite plate to record the amplitude and the natural frequencies of the composite structure. Each composite specimen is then fixed to the surface of …

An Investigation Of Initially Delaminated Composite Sandwich With Delamination Arrest Mechanism Under Buckling Loading, Tony D. Tran

Master's Theses

This thesis involves the development of a fiberglass-foam composite sandwich structure with the introduction of delamination arrestment keys; therefore, a study of an initially delaminated composite sandwich structure was the experimental analysis on multiple configurations in how the arrestment keys are placed.

The first part of this thesis research was to the experimental design and manufacturing of the composite sandwich plates. These plates were later cut down to the specific test dimensions and manufacturing processes for the composite sandwich plates and test specimens were created. The composite sandwich plates were manufactured using a vacuum resin infusion process. The dimensions of …

Human Powered Helicopter, Brenton Haven, Daniel Hudson, Eli Knight

Mechanical Engineering

Fall of 2009, The Cal Poly Aircraft Construction club restarted Cal Poly's quest for the Sikorsky prize. The Sikorsky prize rewards the first a human powered helicopter to sustain controlled hover for one minute without stored energy. Throughout the 1980’s, Cal Poly made three attempts; the most successful being the DaVinci III. Also, the DaVinci III was the first ever publically recognized successful human powered helicopter to leave the ground. This scope of this project is to improve the DaVinci III fuselage and drivetrain for the DaVinci IV. The DaVinci IV adopts the DaVinci III system layout and improves both …

Composite Suspension For Formula Sae Vehicle, Reid Olsen, Andrew Bookholt, Eric Melchiori

Mechanical Engineering

This senior project report describes how a redesign of the 2008 Cal Poly Formula SAE vehicle's suspension components was conducted using carbon fiber components.

Composite Manufacturing Of Small Wind Turbine Blades- Utility Scale Methods Applied To Small Wind, Bryan Kyle Edwards

Master's Theses

Cal Poly, San Luis Obispo’s first wind turbine explores the methods and processes that are employed to manufacture utility scale wind turbines, and applies them to small scale wind turbines. The primary objective is to promote the development of small scale wind turbine blades in ways that resemble, as closely as possible, the construction and methods of utility scale turbine blade manufacturing. Vacuum infusion is employed to create a hollow, multi piece, lightweight design using carbon fiber and fiberglass with an epoxy based resin. A “rapid prototyping” method is developed using high density foam molds that allows short cycle time …

Performance Analysis And Life Prediction For Small Wind Turbine Blades: A Wood Laminate Case Study, Christopher James Nosti

Master's Theses

A detailed study of the fatigue life of wooden wind turbine blades for a new 10 kilowatt system was undertaken. A numerical model of the blades was created using the technical software package MATLAB in order to estimate the maximum stress occurring within the blade in response to changes in wind velocities based on a wind profile approximating the location where these turbines are expected to operate. The material properties of the wooden laminate were measured using an Instron tensile test machine and were found to be in line with published values. In parallel with this effort, a three dimensional …