Structures and Materials Commons^™

Experimental And Theoretical Fracture Analysis Of Rift Manufactured Carbon Fiber-Vinyl Ester Lamina, Daniel Joseph Longo

Theses and Dissertations

This thesis investigates the fracture behavior of unidirectional carbon fiber-vinyl ester (CFVE) laminates manufactured using the Resin Infusion with Flexible Tooling (RIFT) process, a cost-effective alternative to autoclave-based fabrication methods. Composite materials like CFVE are increasingly adopted in high-performance applications due to their high strength-to-weight ratio and corrosion resistance; however, their anisotropic nature presents challenges in predicting crack initiation and propagation. To address this, a comprehensive approach combining experimental testing, finite element modeling (FEM), and classical fracture mechanics was employed. Orthotropic mechanical properties were first determined through tensile and shear tests, providing critical properties for FEM simulations. A series of …

Space Force Spacecraft Hull Inspection: Creation Of A Process To Inspect, Compare, And Fault Detect On The Surface Of A Spacecraft Hull, Ethan Rainsburg

Williams Honors College, Honors Research Projects

The Space Force Inspection design project aims to create a system for scanning the hull of a spacecraft, identifying any damage by cross-checking the new scan with a previous scan, and fixing any identified damage picked up by the scan. This project contains key objectives such as defining testable parameters for any given scanner, creating a repeatable process for comparing scans, and automating the process using open-source code and software. The ideal outcome for this project is to have the fully automated system implemented to a robot that is being designed and manufactured by a sister team. Some of the …

Dynamic Load Identification Using Optimal Sensor Placement And Dynamic Condensation Methods, Iole Pecora

Graduate Theses, Dissertations, and Problem Reports (ETD)

Knowledge of excitation loads that structures experience during their service life is pivotal in different engineering fields, not only from a structural design optimization point of view but also as prevention of possible damages to the structures themselves. However, in case of dynamic events such as tornadoes, structures subjected to impulsive load due to their vicinity of explosions, the excitation load cannot be directly determined through direct measurements. In these scenarios, the inverse problem is used, and it is called load identification. This type of problem tries to determine the excitation load knowing the system response through a series of …

Manufacturability And Analysis Of Topologically Optimized Continuous Fiber Reinforced Composites, Jesus A. Ferrand

Doctoral Dissertations and Master's Theses

Researchers are unlocking the potential of Continuous Fiber Reinforced Composites for producing components with greater strength-to-weight ratios than state of the art metal alloys and unidirectional composites. The key is the emerging technology of topology optimization and advances in additive manufacturing. Topology optimization can fine tune component geometry and fiber placement all while satisfying stress constraints. However, the technology cannot yet robustly guarantee manufacturability. For this reason, substantial post-processing of an optimized design consisting of manual fiber replacement and subsequent Finite Element Analysis (FEA) is still required.

To automate this post-processing in two dimensions, two (2) algorithms were developed. The …

A Comparison Study Of Composite Laminated Plates With Holes Under Tension, Joun S. Kim

Master's Theses

A Comparison Study of Composite Laminated Plates with Holes under Tension

A study was conducted to quantify the accuracy of numerical approximations to deem sufficiency in validating structural composite design, thus minimizing, or even eliminating the need for experimental test. Error values for stress and strain were compared between Finite Element Analysis (FEA) and analytical (Classical Laminated Plate Theory), and FEA and experimental tensile test for two composite plate designs under tension: a cross-ply composite plate design of [(0/90)4]s, and a quasi-isotropic layup design of [02/+45/-45/902]s, each with a single, centered hole of 1/8” diameter, and 1/4" diameter (four sets …

Optimum Design Of Composite Wing Spar Subjected To Fatigue Loadings, Juan Reuben Lazarin

Master's Theses

Composites are now being incorporated into aircraft designs because of their high strength to weight ratio compared to traditional metal materials. Due to the complexity of the material, composite parts are presently being over designed to satisfy static and fatigue requirements. A greater understanding of composite fatigue behavior will allow for even greater weight savings leading to increased fuel economy. A critical part of an aircraft that is subjected to fatigue bending loads are its wings. The forces acting on the wings include its lift distribution, powerplant, and fuel which can be carried in the wing body. When in flight …

Design, Manufacture, Dynamic Testing, And Finite Element Analysis Of A Composite 6u Cubesat, Yanina Soledad Hallak

Master's Theses

CubeSats, specially the 6U standard, is nowadays the tendency where many developers point towards. The upscaling size of the standard and payloads entail the increase of the satellite overall mass. Composite materials have demonstrated the ability to fulfill expectations like reducing structural masses, having been applied to different types of spacecraft, including small satellites.

This Thesis is focused on designing, manufacturing, and dynamic testing of a 6U CubeSat made of carbon fiber, fiberglass, and aluminum.

The main objective of this study was obtaining a mass reduction of a 6U CubeSat structure, maintaining the stiffness and strength. Considering the thermal effects …

Composite I-Beam Fabrication And Testing In Response To 14th Annual Sampe Bridge Competition, Kodi Rider, Niño Noel Las Piñas, Hans Mayta

Aerospace Engineering

Composites are a type of material that generally combines two materials yielding mechanical properties that are different than its constituent parts. These constituents are classified as either a fiber or a matrix. The objective of this project is to create a carbon-fiber composite I-beam that meets the specifications of the SAMPE student bridge competition. The I-beam consists of carbon fiber unidirectional and woven laminas, as well as aluminum honeycomb and high density polystyrene foam to stiffen the structure. The bridge contest rules limit the dimensions and weight of the bridge. The cross-section must be within 4 inches x 4 inches …

Matlab Structural Analysis Code For String Wing Box Structure, Sean Brown

Aerospace Engineering

This report outlines the method used for analysis of a wing box structure for the experimental “stringy” wing structure often used in light RC aircraft. This code is able to find the displacement of each joint, and the stress and forces in each member of the truss structure. It also has the features of load and structure visualization, Kevlar string removal, user-defined point and distributed loading functions, and user-defined failure criteria function. This method and resulting code is meant for use in the support of the Human Powered Helicopter project being undertaken by the Aerospace and Mechanical Engineering Department at …

Design, Fabrication, Structural Testing, And Numerical Analysis Of A Small Scale Composite Wing, Jacob David Gaunt, Juan Carlos Flores, Vincent Andrew Perry

Aerospace Engineering

A small scale composite wing based on a design found on an experimental aircraft was designed, constructed, and tested dynamically and statically. The wing was constructed similarly to an experimental aircraft wing. The performed static test was intended to produce pure bending. Strain gages were used to measure strains on the wing structure. The strains were converted to stresses to aid in analysis. The static test results suggested that the wing was actually under torsion. Four structural modes were found from the static test. A finite element analysis model was made to compare experimental results to numerical analytical results. The …