Manufacturing Commons^™

Direct Ink Writing Of Functional Fiber/Granular Composites, Zhuoyuan Yang

Doctoral Dissertations and Master's Theses

Direct ink writing provides a versatile manufacturing route for fabricating functional fiber and granular composites with controlled architecture, tunable interfaces, and customized material distributions. Fiber reinforced composites offer high stiffness, strength, fatigue resistance, and functional anisotropy, while granular composites provide scalable access to particle based structures with high material efficiency and broad resource compatibility. However, the additive manufacturing of these composite systems remains challenging. For fiber based composites, precise control of fiber placement, matrix impregnation, interfacial bonding, and freestanding deposition is difficult to achieve during printing. For granular composites, stable particle flow, controllable packing, binder infiltration, and shape retention are …

Study Of Electrospun Nanocomposite Nanofiber Nonwoven Mats With Precursor Solutions Prepared By Ultrasonic Processing, Stephanie Tussey

All Dissertations

Understanding the complexity of changes in a polymer solution through the addition of nanoparticles and the process used to prepare the solutions is vitally important to obtain desirable characteristics of electrospun nanofibers such as degree of crystallinity, morphological, thermal and mechanical properties. Although there have been significant efforts in this research area, a more in-depth understanding on how nanoparticles can affect the formation of polymeric structures during electrospinning is still needed to ensure overall quality and performance of the nonwoven material. The present study aimed to specifically explore the relationship between solution processing method, nanoparticle volume fraction, and solution properties …

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 …

Flexure Properties Of 3d Printed Nylon Carbon Fiber Composite And Stiffness Of 3d Printed Modified Cuttlefish Bone Structure, Shashikanth Reddy

Electronic Theses and Dissertations

Flexure strength is one of the most widely used mechanical properties to represent the mechanical behavior of the composite. Fiber reinforcements increase the flexure strength of a composite. Specifically, there has been tremendous growth in the use of Carbon Fiber (CF) in the manufacturing industry due to its significant contribution to enhance the mechanical properties of a composite. Fiber orientation, void content, bonding between the layers (delamination), and fiber distribution are some of the factors that affect the flexure strength of a reinforced composite. The laminate (composite with reinforced layers) composites, has been a focus of study by researchers from …

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.

Design Survey Of Laminated Composite I-Beam, Mrinmoy Saha

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Composite I-beams are popular for high-strength low-weight applications. Learning the macro-mechanics and designing the composite I-beam properly are necessary. In this report, a design overview of the composite I-beam is discussed which is based on classical lamination theory where it includes the homogenization approach, the plane stress assumption and the Kirchhoff hypothesis. Using these assumptions, a method was developed to come up with the effective material properties of a beam. Formulas to calculate maximum deflection and maximum bending stress and shear stress and the stress concentration at the connection of web-flange are discussed which describe ways for designing and manufacturing …

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 …

Aluminum Matrix Syntactic Foam Fabricated With Additive Manufacturing, M. Spratt, Joseph William Newkirk, K. Chandrashekhara

Materials Science and Engineering Faculty Research & Creative Works

Syntactic foams are lightweight structural composites with hollow reinforcing particles embedded in a soft matrix. These materials have applications in transportation, packaging, and armor due to properties such as relatively high specific stiffness, acoustic dampening, and impact absorption. Aluminum matrices are the most widely studied of metal matrix syntactic foams, but there is little to no research in regards to processing the foams with additive manufacturing. It is theorized that the fast cooling rates and limited kinetic energy input of additive could reduce two issues commonly associated with processing syntactic foams: microsphere flotation in the melt and microsphere fracture during …

Open Source Multi-Head 3d Printer For Polymer-Metal Composite Component Manufacturing, J. Laureto, Joshua M. Pearce

Department of Materials Science and Engineering Publications

As low-cost desktop 3D printing is now dominated by free and open source self-replicating rapid prototype (RepRap) derivatives, there is an intense interest in extending the scope of potential applications to manufacturing. This study describes a manufacturing technology that enables a constrained set of polymer-metal composite components. This paper provides (1) free and open source hardware and (2) software for printing systems that achieves metal wire embedment into a polymer matrix 3D-printed part via a novel weaving and wrapping method using (3) OpenSCAD and parametric coding for customized g-code commands. Composite parts are evaluated from the technical viability of manufacturing …

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 …

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 …

Utilizing Reprap Style 3d Printers For The Manufacturing Of Composite Heat Exchangers, John Laureto

Dissertations, Master's Theses and Master's Reports

The low cost 3D printing market is currently dominated by the application of RepRap (self-replicating rapid-prototyper) variants. Presented in this document are practical utilizations of RepRap technology. Developed are innovative processes to manufacture composite materials systems for thermal management solutions.

First, a laser polymer welder system is validated by quantifying maximum peak load and weld width of linear low density polyethylene (LLDPE) lap welds as a function of linear energy density. The development of practical engineering data, in this application, is critical to producing mechanically durable welds. Developed laser and printer parameter sets allow for manufacturing of LLDPE multi-layered heat …

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 …

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.

Advanced Design Optimization For Composite Structure: Stress Reduction, Weight Decrease And Manufacturing Cost Savings, Shayan Ahmadian

Master's Theses

An injection moldable chopped fiber composite actuator with detailed drawing and tolerances was designed within one year. A vendor was selected and a quote for injection molding tooling cost for production was obtained and the first prototype was built in addition of six months. The risks are identified and material characterization tests are proposed.

The objective of this project was redesigning an aluminum made actuator with a continuous fiber composite for weight saving purposes. After searching the literature and consulting with experts in the field it was concluded that manufacturing costs associated with continuous fiber composite are 3 times as …

Natural Fibers And Fiberglass: A Technical And Economic Comparison, Justin Andrew Zsiros

Theses and Dissertations

Natural fibers have received attention in recent years because of their minimal environmental impact, reasonably good properties, and low cost. There is a wide variety of natural fibers suitable for composite applications, the most common of which is flax. Flax has advantages in tensile strength, light weight, and low cost over other natural fibers. As with other natural and synthetic fibers, flax is used to reinforce both thermoset and thermoplastic matrices. When flax is used in thermoplastic matrices, polypropylene and polyethylene are the main resins used. Although at first glance flax may seem to be a cheaper alternative to fiberglass, …