Structural Materials Commons^™

Mechanical Characterization Of Automated Fiber Placement And Additive Manufacturing Hybrid Composites, Lucan Haviland

Electronic Theses and Dissertations

This thesis presents the optimization of processing parameters based on the mechanical properties of Continuous Fiber-Reinforced Thermoplastic (CFRTP) Unidirectional (UD) consolidated tapes. The UD tapes were consolidated using an AFP head and a thermoforming press for comparison. The adhesive strength of hybrid parts consisting of CFRTP UD tape bonded to a 3D-printed substrate with the same matrix system were investigated. Large Area Additive Manufacturing (LAAM) was utilized for the 3D-printed parts. Different types of thermoplastic composite materials were explored, including Glass Fiber reinforced Polyethylene Terephthalate Glycol (GF/PETG), Carbon Fiber reinforced Polyethylene Terephthalate Glycol (CF/PETG), Carbon Fiber reinforced Polycarbonate (CF/PC), and …

Refractory High-Entropy Alloys: Design, Fabrication, Characterization, And Nanoparticle Synthesis, John Hutson Whitlow

Masters Theses

High-Entropy Alloys have been a highly researched area of metals ever since their introduction in 2004 by Brian Cantor and Jien-Weh Yeh. In the continued research of High-Entropy Alloys (HEAs), a specific area concerning Refractory High-Entropy Alloys (RHEAs) has emerged for their high-temperature applications. Although RHEAs have maintained high strength and toughness at high temperatures, their low ductility still needs to be addressed. A dataset was created to find correlations between various characteristics of RHEAs and their composition. A set of seven compositions were selected and fabricated. Mechanical tests were run on the seven compositions, and a proposal was written …

Investigation Of Microstructure And Mechanical Behavior Of Novel Powder-Extruded Al-Ce-Mg Alloys, Mairym Vazquez

Doctoral Dissertations

Pursuing advanced structural materials with enhanced performance, reduced weight, and lower costs is a constant endeavor in the aerospace and automotive industries. Conventional structural alloys, such as cast irons, carbon steels, and titanium alloys, have strength, weight, and cost limitations. Aluminum-based alloys, known for their lightweight and high strength, have gained popularity in these industries. This dissertation focuses on investigating microstructure and mechanical behavior of novel powder-extruded Al-Ce-Mg alloys as potential candidates for high-performance structural materials.

This research explores using powder extrusion, a well-established forging methodology in the steel industry, to produce Al-Ce-Mg alloys with improved properties and aims to …

A Spike-Shaped Anchorage For Steel Reinforced Polymer (Srp)-Strengthened Concrete Structures, Xingxing Zou, Keenan L. Mcburney, Lesley H. Sneed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel reinforced polymer (SRP) composite has recently emerged as an effective and economical solution for strengthening of reinforced concrete (RC) structures. Premature debonding failure of unanchored SRP at low load levels generally governs the performance of RC structures strengthened with externally bonded SRP. Therefore, a novel yet simple spike-shaped anchorage system was proposed in this study to prevent the debonding failure of SRP and to improve the interfacial shear capacity. Experimental investigation through single-lap shear tests of SRP-concrete joints showed that the anchorage system changed the failure mode from composite debonding to fiber rupture. In addition, the anchorage system substantially …

Interlaminar Tensile Properties Of Unidirectional And Woven Carbon Fiber Reinforced Toughened Epoxy Laminates, Eric Timothy Casey, Sean Mckalip Thompson

Materials Engineering

This project aims to develop a dataset on interlaminar tensile strength comparing unidirectional and woven thermoset matrix carbon fiber composites keeping ply count, matrix material, and fiber diameter constant. The interlaminar tensile strength is an important property relating to the delamination failure mode. Interlaminar tensile strength is determined using the ASTM D6415 testing standard. This test is a modified four-point bend test using a 90° curved beam test specimen. Laminates were produced by laying up pre-impregnated carbon fiber sheets onto a curved beam tooling. The unidirectional laminate was produced with 20 plies in a [0,0,90,0,0]₄ layup pattern. The woven …

Synthesis And Characterization Of Sodium Cathode Materials, He Zhou

McKelvey School of Engineering Theses & Dissertations

As sodium batteries hold great promise as a next-generation energy storage device to replace lithium batteries, the development of sodium battery materials has become increasingly urgent. The current study aims to investigate two potential sodium-ion battery cathode materials, Sodium Vanadium Phosphate, and Sodium Manganese Hexacyanoferrate, optimize the experimental procedures, conduct a systematic analysis of material properties and characterization, and ultimately determine the ideal synthesis conditions for these materials.

In the first part of the study, we focused on optimizing the synthesis of Sodium Vanadium Phosphate. By investigating various synthesis conditions, such as annealing temperature, pressure, ascorbic acid content, and material …

Study Of A Carbon Fiber Reinforced Polymer Composite Using A Biobased Polyurethane As A Thermosetting Resin, Teddy Mageto

Electronic Theses & Dissertations

Carbon Fiber Reinforced Polymer composites (CFRP) have garnered increasing interest in recent years especially in the aerospace and automobile industries where they are gradually replacing metals as structural materials. This is owing to their light weight, high strength, high modulus, and excellent strength-to-weight ratio. Polymers are typically used as thermosetting resins in these composites. However, the synthesis of polymers currently is conducted via petrochemical processes which leads to adverse effects on the environment. To this end, in this work a biobased Polyurethane (PU) was used as a thermosetting resin in a CFRP. The biobased PU was synthesized by the reaction …

Mechanics And Mechanisms Of Fracture For An Eastern Spruce Subject To Transverse Loading Using Acoustic Emission, Parinaz Belalpour Dastjerdi

Electronic Theses and Dissertations

Due to its excellent structural qualities and accessibility, wood is among the most often utilized structural materials. Despite its ubiquity, wood poses numerous challenges. It is heterogeneous and anisotropic. It has a complex hierarchical ultrastructure, and the properties can have wide variation within a species, and indeed within an individual tree. This work aims to improve our understanding of the strength and fracture behavior of spruce-pine-fir (south) (SPFs), particularly in cross-grain direction. This study’s primary goal is to examine the relationship between crack propagation and cross grain morphology under the following loading configurations: compact tension, compression, and rolling shear. The …

Efficient Sintering Of Lunar Soil Using Concentrated Sunlight, Diprajit Biswas

Electronic Theses and Dissertations

Construction material is one crucial need for long-term habitation on the moon. When concentrated for high heat flux, solar radiation can heat lunar soil or regolith until it sinters at temperatures above 900°C. The solid, sintered soil simulant can be used as construction material. This work explores the conditions leading to effective lunar soil sintering for both direct and indirect irradiated sintering. Lunar soil simulants were sintered using concentrated light from a xenon-arc lamp with varying heat flux intensity. During direct sintering of LHS-1, a sintering range of 860°C-1140°C corresponding to a peak heat flux of 105-120 kW/m2 was identified …

Machine Learning-Based Data And Model Driven Bayesian Uncertanity Quantification Of Inverse Problems For Suspended Non-Structural System, Zhiyuan Qin

All Dissertations

Inverse problems involve extracting the internal structure of a physical system from noisy measurement data. In many fields, the Bayesian inference is used to address the ill-conditioned nature of the inverse problem by incorporating prior information through an initial distribution. In the nonparametric Bayesian framework, surrogate models such as Gaussian Processes or Deep Neural Networks are used as flexible and effective probabilistic modeling tools to overcome the high-dimensional curse and reduce computational costs. In practical systems and computer models, uncertainties can be addressed through parameter calibration, sensitivity analysis, and uncertainty quantification, leading to improved reliability and robustness of decision and …

Comparative Analysis On Low Cost Continuous Carbon Fiber Polypropylene Composite Using Compression Molding And Automated Tape Placement, Benjamin U. Schwartz

Masters Theses

Carbon fiber reinforced plastics (CFRP) are widely used throughout the aerospace industry where a weight reduction remains the highest priority with less emphasis on cost. Textile grade carbon fiber (TCF) and other low cost carbon fiber (LCCF) alternatives have recently emerged for use in the automotive market where emissions regulations have pushed automotive manufacturers and research institutions to look for cost effective light weight materials. Fiber reinforced thermoplastics provide an effective solution that align with automotive design including low cost, high processing rates, high impact toughness, unlimited shelf life, and recyclability.

TCF and Zoltek_PX35 fibers are two LCCF aimed at …

Optical Fiber Tip Micro Anemometer [U.S. Patent Us11635315b2], Hengky Chandrahalim, Jeremiah C. Williams

Faculty Publications

A passive microscopic flow sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fiber. The three-dimensional microscopic optical structure includes a post attached off-center to and extending longitudinally from the cleaved tip of the optical fiber. A rotor of the three-dimensional microscopic optical structure is received for rotation on the post. The rotor has more than one blade. Each blade has a reflective undersurface that reflects a light signal back through the optical fiber when center aligned with the optical fiber, the blades of the rotor shaped to rotate at a rate related to …

Correlation Between Laboratory Testing Results And In-Situ Sidewalk Scaling, Brian R. Shea

Masters Theses

Scaling tests aim to induce scaling behavior in concrete specimens similar to environmental conditions. The efficacy of laboratory tests’ ability to match environmental conditions is important to be able to evaluate the durability of concrete exposed to freeze-thaw cycles and de-icers. This study attempts to correlate results between two existing scaling test standards, ASTM C672 and the BNQ NQ 2621-900. The correlation is done via scaling evaluation including computer-based photogrammetric analysis, visual ratings, and cumulative mass loss measurements. Then a correlation between the laboratory testing and in-situ sidewalk panel specimens is made via visual ratings.

Beirut Arab University - Faculty Of Engineering - Newsletter Issue 0, Faculty Of Engineering, Beirut Arab University

Engineering Newsletters

No abstract provided.

Mechanical Property Of Body-Thoroughly Enhanced Austenitic Stainless Steel And High-Mn Steel By Industry-Applicable 3-Axis Stress-Released Impact, Busheng Zhang

Electronic Thesis and Dissertation Repository

As two important austenitic steels, the austenitic stainless steel (SS) and austenitic high-Mn steel have been seeking a decent yield strength to match their versatile exceptional advantages. However, the traditional, severe, and high-strain-rate plastic deformation techniques currently used to strengthen the austenitic steels, are limited by their ability to produce ultrastrong steel, bulk sized steel, and the fracturing risk they pose to the steel, respectively. In this research, we propose an industry-applicable 3-axis stress-released impact process, which addresses the challenges facing the current techniques and successfully prepares the body-thorough ultrastrong and ductile austenitic steels without fracturing risk.

The bulk 316L …

Precious Plastics - Plastic Brick Machine Fabrication, Timothy Ukaobasi Kanu, Evi Paraskevi Troulis

Architectural Engineering

The goal of this research is to determine the structural parameters of the recycled plastic polypropylene when molded into bricks resembling CMU blocks. To accomplish this, three mechanisms had to be assembled: the shredder, the injector, and the 1x1 mold. A tensile and compression test were to be performed on the plastic brick, and the values would be used to compare the tensile and compressive strength of PP plastic bricks, as well as their modulus of elasticity and stress vs. Strain performance. These values would be analyzed to determine whether it would be feasible to build an entire plastic wall. …

Atomistic Simulation Studies Of Thin Film Growth And Plastic Deformation In Metals And Metal/Ceramic Nanostructures, Reza Namakian

LSU Doctoral Dissertations

Despite the significant improvements in manufacturing and synthesis processes of metals and ceramics in the past decades, there are still areas in which the procedure is still frequently more of an art or skill rather than a science. Therefore, systematic and combined experimental and computational studies are required to facilitate the development of techniques that offer thorough understanding of the events taking place during manufacturing and synthesis processes. With regard to these issues, it is paramount to address microscale characterizations and atomic scale understanding of the events during fabrication processes. One of the focuses of this study is unraveling fundamental …

Freespan Analysis For Subsea Pipeline Integrity Management Strategy, Nurul Hadi, Muhammad Helmi, Edo Cathaputra, Dedi Priadi, Donanta Dhaneswara

Journal of Materials Exploration and Findings (JMEF)

Abstract. Over a rough seabed or on seabed subject to scour, freespans can occur when contact between a subsea pipeline and the seabed is lost over an acceptable distance. When this exceeds the allowable freespan length, design stresses can be exceeded, and a vortex induced vibration (VIV) response can be initiated, resulting in the risk of fatigue failure. If this is not predicted and controlled properly, it will affect pipeline integrity, leading to expensive rectification and intervention work. Freespan analysis consisted primarily of a screening check in which the as-found freespans from Remotely Operated Vehicle (ROV) or multibeam Side …

Investigation Of Microstructurally Dependent Mechanical Properties Of Cold Sprayed Copper Using Correlative Microscopy, Quintin Otto

UNF Graduate Theses and Dissertations

This project employs multi-instrument materials characterization to analyze material made with the “Cold Spray” additive manufacturing process. Cold spray is an emerging additive manufacturing technique with unique benefits resulting from its low temperature adhesion process induced by plastic deformation. Metallic powder collides at high speeds creating three dimensional materials and coatings without the need for melting. Copper cold sprayed specimens were analyzed using a series of imaging techniques to characterize the microstructure at varying levels of detail and magnification. Scanning electron microscopy and electron back scattered diffraction were paired with microhardness testing to generate a correlative comparison between microstructure and …

Development Of Inconel 718f And Inconel 718e Powders For Parts Manufacturing Utilizing Binder Jet Three-Dimensional Printing And Compressed Pellet Methods, Duncan Eric Manor Ii

Graduate Theses, Dissertations, and Problem Reports

Alloy Inconel 718 is a Ni based superalloy used for high temperature applications including turbine blades, turbocharger rotors and nuclear reactors. Inconel 718 is a popular commercial atomized powder that has limitations in performance for use in additive manufacturing applications due to poor part quality and efficiency of current fabrication methods. Developing new compositions and additive manufacturing (AM) methodologies of IN718 is critical to improve the quality and the efficiency of IN718 parts manufacturing. Developing new additive manufacturing methodology that produces higher quality parts made of IN718 as compared to current methods has the potential to greatly impact industry, academia, …