Manufacturing Commons^™

Detecting And Repairing Conflicting Constraints In Co-Trained Physics-Informed Neural Networks For Composite Curing Processes, Cooper J. Evans

Dissertations, Master's Theses and Master's Reports

Composite materials have become a critical component of modern manufacturing, especially in the automotive and aerospace industries. The curing process for these composites has been modeled using a variety of partial differential equations representing the heat transfer and composite curing kinetics. Optimizing the applied temperature profile is critical for maximizing the efficiency and capacity of composite part manufacturers. Constraints must be placed on the inputs and outputs of the model, including but not limited to, the applied temperature profile, part temperature, and final degree of cure. Conflicting sets of constraints are easy to unknowingly impose due to the highly coupled …

Biobased Acrylate Composites With Enhanced Strength For Additive Manufacturing, Nicole Wagner, Joseph Mcwherter

Engineering Faculty Articles and Research

With the expanding use of polymers in additive manufacturing, sustainable resins for use in vat photopolymerization are required to reduce their environmental impact. One promising approach to achieve this is to incorporate biobased fillers that replace the acrylates in photopolymer resins as ‘green’ alternatives. In this study, photopolymer composites consisting of a methacrylate resin with varying calcium carbonate powder content between 0 and 50 wt.% were investigated. A digital light processing technique was used to fabricate tensile test specimens for mechanical testing. Good printability, dimensional accuracy, and good interlayer adhesion were observed for composite resin formulations that incorporated calcium carbonate …

Natural Fiber Reinforced Composites For Sustainable Additive Manufacturing., Athira Nair Surendran

Electronic Theses and Dissertations

Carbon fiber is widely known for its exceptional strength, making it a sought-after material in composite manufacturing, especially with thermosets and thermoplastics. Its major applications span aerospace, wind turbines, sports equipment, automotive interior and exterior parts, robotics and medical equipment. Recently, carbon fiber filament manufacturing has gained attention due to the availability of desktop 3D printers and the versatility and customizability that comes with the realm of 3D printing. Commercial carbon fiber production, primarily from polyacrylonitrile (PAN), is energy-intensive and derived from crude oil, contributing to significant environmental impacts and poor recyclability. Alternatively, lignocellulosic natural fibers present a possible sustainable …

A Survey On Fused Filament Fabrication To Produce Functionally Gradient Materials, Arup Dey, Monsuru Ramoni, Nita Yodo

Manufacturing & Industrial Engineering Faculty Publications

Fused filament fabrication (FFF) is a key extrusion-based additive manufacturing (AM) process for fabricating components from polymers and their composites. Functionally gradient materials (FGMs) exhibit spatially varying properties by modulating chemical compositions, microstructures, and design attributes, offering enhanced performance over homogeneous materials and conventional composites. These materials are pivotal in aerospace, automotive, and medical applications, where the optimization of weight, cost, and functional properties is critical. Conventional FGM manufacturing techniques are hindered by complexity, high costs, and limited precision. AM, particularly FFF, presents a promising alternative for FGM production, though its application is predominantly confined to research settings. This paper …

Kissing Bond Assessment In Adhesive Bonded Carbon Fiber Reinforced Composites Using Dielectric Spectroscopy, Minhazur Rahman

Mechanical and Aerospace Engineering Dissertations - Archive

The widespread use of fiber-reinforced composites in industries such as space, aviation, automobiles, and construction necessitates the formation of robust composite joints between critical structural components. Although adhesive-bonded joints are superior with improved load distribution and reduced weight, they are often overlooked in favor of bolted joints and mechanical fasteners due to the lack of reliable Non-Destructive Evaluation (NDE) techniques for adhesive-bonded composites. The anisotropic nature of the substrate and the intricate interfacial interactions between the adherend and adhesive material present significant challenges for conventional NDE methods. Moreover, weak adhesive bonds can result from uncontrolled manufacturing parameters, such as accidental …

Anisotropic Material Behavior Of 3d Printed Fiber Composites, Jordan Garcia

Theses and Dissertations--Mechanical and Aerospace Engineering

Literature has shown that 3D printed composites may have highly anisotropic mechanical properties due to variation in microstructure as a result of filament deposition process. Laminate composite theory, which is already used for composite products, has been proposed as an effective method for quantifying these mechanical characteristics. Starting with the analysis of comparing the printing orientation of premanufactured carbon fiber reinforced filament, the mechanical properties of 3D printed objects were examined. The mechanical properties changed not only as a result of machine choice, but how the sample is oriented along the printing bed. The analysis continued with looking at the …

Investigation Of Manufacturing Techniques For Magnetorheological Elastomers To Expand Feasibility In A Diverse Array Of Applications, Austin S. Robbins

College of Graduate Studies: Theses & Dissertations

Magnetorheological elastomers, or MREs, are smart composite materials with controllable physical and mechanical properties when introduced to an external stimulus of a magnetic field. The controllability of these properties is highly tunable by the selection of the elastomeric matrix, concentration of magnetically permeable particles, introduction of additives, and the alignment of the constituents during the curing process. The fabrication of MREs typically calls for a mold that is filled with an MRE mixture to create the final desired geometry after curing. These molds are frequently placed under a magnetic field which orients the micron sized magnetic particles along the magnetic …

Durability Of Vacuum Infusion Tooling Produced From Fused Granular Fabrication Additive Manufacturing, Nathan Northrup, Jason Weaver, Andy R. George

Faculty Publications

Large area additive manufacturing (LAAM) has the capability to create tooling that is lower cost than conventionally manufactured tooling and still has sufficient properties for many applications. A vacuum infusion mold was printed from fiberglass-ABS and evaluated for wear and suitability for small vacuum infusion runs. The mold was designed to accentuate high wear as a “worst case” scenario. The mold was able to produce 10 parts successfully before any noticeable change occurred to the surface finish. By 14 parts, the surface finish had roughened sufficiently that demolding was difficult and resulted in damage to the part. Profilometry measurements showed …

Vacuum Infusion Of Composites: Durability Of Hybrid Large Area Additive Tooling For Vacuum Infusion Of Composites, Nathan Northrup, Jason Weaver, Andy R. George

Faculty Publications

The durability of a hybrid large area additively manufactured fiberglass ABS mold for vacuum infusion of composites was evaluated. The validation was done by designing and fabricating a mold for a custom test artifact and analyzing the surface geometry over the course of multiple infusions until tool failure. After printing and machining, the mold required a sealer to maintain vacuum integrity. The mold was able to produce 10 parts successfully before the sealed tool surface began to tangibly roughen, resulting in increased difficulty of demolding and a rougher surface finish. After the 14th infusion, the part required destructive force to …

Tensile Testing Environmental Chamber – Structural, Michael Ingel, Erik Soldenwagner, Austin Marshall, Lauren Schirle

Mechanical Engineering

Environmental chambers for tensile testing machines are used to study how a multitude of materials behave in extreme temperatures. These chambers provide the necessary information to innovate cutting edge technology for materials in fields such as aerospace. These chambers are often heavy and expensive requiring a significant amount of time and money just in the installation process alone. This report will serve to outline and define the design and fabrication of an environmental chamber, conducted by a team of four senior mechanical engineering students at California Polytechnic State University, San Luis Obispo. The goals of the project include a low-weight …

Enduro Campers, Ryan J. Shomsky, Alexander W. Horst, Kevin S. Pickering, Jackson L. Aplanalp, Luke Arana, Will Firestone

Mechanical Engineering

The Enduro Campers senior project team (Formerly known as Lobo Campers senior project team) was recruited by Mr. Leif Stein to assist in the design, manufacturing, and testing of the materials and components of his company’s expedition box camper. The two main focuses of the project, divided into two sub-teams, were on the testing and manufacturing process of the materials used in the camper, and on the design and analysis of the camper’s access door, step box, and other subsystems.

The focus of the materials analysis and manufacturing team was based around the design parameter to use composite sandwich panels …

Cal Poly Prove Lab Endurance Car Composite Body Paneling Design, Emma Wheelock, Sarah Rutland, Noah Fisher, Brian Menard

Mechanical Engineering

The Cal Poly Prototype Vehicles Laboratory (PROVE Lab) needs a body paneling design for their Endurance Car aeroshell which optimizes strength, weight and accessibility while minimizing complexity. Additionally, a low-complexity, accurate manufacturing process for the PROVE Lab Endurance Car aeroshell needs to be developed. PROVE Lab designed the shape of the aeroshell. The aeroshell will serve to reduce the aerodynamic drag on the car at high speed, and is not a structural component of the car. Due to the high-strength and lightweight nature of composites, PROVE Lab requests the senior project team investigate using composites for automotive body paneling applications. …

Composite Lattice Tooling, Rachel Greene, Isaiah De Leon, Patrick O'Donnell, Alec Fuoti

Mechanical Engineering

Composite lattice structures allow for a high strength to weight ratio which is favorable in the aerospace industry where mass is a driving design consideration. Maxar Technologies has tasked the senior project team with creating a process and subsequent tooling to effectively manufacture their patented composite lattice structure as shown in United States patent #10326209B2. The only current industry solution to manufacture similar structures is Isotruss’s utilization of filament winding. The project team was asked to deliver a two-cube-by-four-cube lattice structure manufactured for properties testing and proof of a working manufacturing process. They also required that the process is well …

Novel Methods For Composites Recycling Via Pyrolysis, Matt Jacobs

Undergraduate Honors Theses

Composites are unique materials in many respects. When fabric woven from carbon fibers is joined with a thermoset resin in a controlled environment, it results in a very strong material, especially evaluated on a pound-for-pound basis against metals and ceramics. One aspect of this construction that provides great strength lies in the fiber-matrix adhesion which facilitates load transfer to the reinforcement of the composite. This fiber-matrix adhesion is promoted by the polarity of the usual thermoset matrices, and properly designed sizing materials coating the fibers. It’s a two-edged sword, though. Although the resin and the fibers are quite strong together, …

C6 Wheels, Samuel L. Pizot, Luke Martin, Josh Warner, Jonah Levis

Mechanical Engineering

This document details the C6 Wheels project being undertaken for senior design. The objective is to design and manufacture carbon fiber reinforced polymer wheels for the Cal Poly Formula Society of Automotive Engineers (FSAE) team. The wheel shells will be used on FSAE’s competition vehicles. FSAE requested the wheels to improve the handling characteristics of their vehicles by reducing the unsprung and rotational mass. They have attempted carbon fiber wheels previously but have not yet run any on their vehicles. FSAE specifically proposed the design of carbon fiber shells with an aluminum center as opposed to full carbon fiber wheels …

Investigation Of Design, Manufacture, Analysis, And Test Of A Composite Connecting Rod Under Compression, Thomas Juhl Rohrbach

Master's Theses

Composite materials hold great potential for the replacement of traditional materials in machines utilized on a daily basis. One such example is within an engine block assembly where massive components inherently reduce the efficiency of the system they constitute. By replacing metal elements such as connecting rods, cylinder caps, or a crank shaft with composite alternatives, a significant increase in performance may be achieved with respect to mechanical strength, thermal stability, and durability, while also reducing mass. Exploration of this technology applied to a connecting rod geometry was investigated through a combination of process development, manufacturing, numerical analysis and testing. …

Prove Endurance Car Front Suspension, Lauren A. Williams, Logan Simon, Justine G. Kwan

Mechanical Engineering

This document details the collaborative Mechanical Engineering Senior Project with Cal Poly PROVE Lab on PROVE Lab’s Project 2; an electric vehicle designed to travel 1000 miles on a single charge. Logan Simon, Justine Kwan, and Lauren Williams are given the challenge of designing an innovative proof of concept front suspension suspension for this vehicle.

After detailed research of new suspension systems, it was determined that the innovative nature could be in the form of unique manufacturing methods, materials use, or mechanical design. At this point in time, this vehicle is a purely conceptual design with no concrete requirements. Therefore …

Drawing And Twisting Of Graphene Fibers, Gregory T. Lane, Robert J. Sekerak, Isaias Diaz

Mechanical Engineering

The aim of this project was to develop a more automated process for drawing and twisting of graphene fibers than was currently in place. This was implemented by having two chemical baths with variable speed rollers at either end, and intermediate roller to spool fiber between stages, and a twisting cylinder with integral spool to twist the fiber as it is collected. The goal was to have this first iteration deliver a working prototype, however due to manufacturing delays and timing constraints, that will be missed. A second follow-on project would be able to continue the work presented here and …

Advances In Composite Manufacturing Of Helicopter Parts, Tobias A. Weber, Hans-Joachim K. Ruff-Stahl

International Journal of Aviation, Aeronautics, and Aerospace

This study investigates and compares different methods for improving standard autoclave composite manufacturing in order to find suitable approaches to a more efficient composite production. The goal is not only a reduction in manufacturing times and costs but also quality enhancement. Improved part quality while decreasing costs enables a manufacturer of composite parts to expand its market share, especially in the helicopter market, which has been constantly shrinking over the last two years. Various approaches such as improved tooling technology, the use of automated systems for lamination as well as outsourcing are examined to provide an overview of possible advancements …

Fiber Length Attrition In Additive Manufacturing, Michael Chapiro

Materials Engineering

Chopped carbon fibers are used as reinforcements in thermoplastics, but the viscous shear forces that arise in melt-processing reduces the fiber length well below its critical length resulting in only moderate strength and stiffness gains compared to the neat resin. This research project aimed to experimentally determine the effect of the melt–flow portion of a single-screw- extrusion process on carbon fiber length attrition in isolation from the immediately preceding screw–plastication step that is responsible for most of the heat needed for melting. Carbon fibers with an initial length of 2 mm were stirred into 5,000 centipoise and 10,000 centipoise silicone …

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.

Wolfpack Gear Inc. Composite Frame Firefighter Backpack, Gabriel Mountjoy, Blair Ridings, Carl Drummond Buchenroth

Mechanical Engineering

No abstract provided.

Feasibility Analysis For Electrically-Powered Hoverboard, Cameron Chan, Jason Cortez, Jay Lopez

Aerospace Engineering

Composite materials are engineered by combining two or more constituent materials with significantly different physical or chemical properties in such a way that the constituents are still distinguishable, and not fully blended. Due to today’s high rising prices of gasoline and aviation fuel costs, many manufacturers have turned to the use of lightweight composites in their designs due to the advantages of the composite material, which include outstanding strength, excellent durability, high heat resistance, and significant weight reduction that the composite material properties hold. The purpose of this project is to design and construct a composite structure for an electrically-powered …

Manufacture, Characterization, And Application Of Multiwall Carbon Nanotube Composite Crylonitrile-Butadiene-Styrene, Daniel Ray Bortz

University of Kentucky Master's Theses

Carbon nanotubes have been studied for nearly two decades and their amazing properties continue to spur intense investigation in the area of polymer composites. In terms of potential commercialization, mutiwall carbon nanotubes (MWCNTs) are currently the most prevalent and economically viable form of nanotubes. Uncovering innovative means to take full advantage of their properties remains a fundamental issue. In this thesis, viability of their use to reinforce polymeric systems is reported. Acrylonitrilebutadiene- styrene (ABS) was used as the host matrix. MWCNTs were introduced to the ABS matrix via melt compounding. The resulting composite was thoroughly rheologically, thermally, and mechanically characterized. …

A Method For Winding Advanced Composites Of Unconventional Shapes Using Continuous And Aligned Fibers, Abraham K. Allen

Theses and Dissertations

Advanced composites are extremely strong, rigid, and light, even when compared with advanced metals. Advanced composites are replacing high-tech metals as the material of choice for aerospace engineering. However, the processes used to manufacture advanced composites generally lose some of the properties of the materials by their process limitations.

One process that keeps the theoretically awesome qualities of the composite materials in tact is filament winding. Filament wound parts are used as rocket shells, bicycle frame tubes, drive shafts, pressure vessels, etc. Filament winding is an automated process and makes reliable parts to close tolerances. If a straight tube were …