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Studies Of Damage Tolerance In Automated Fiber Placement Based Heterogeneous Meso-Architectured Carbon/ Epoxy Composite Laminates., Karan Kodagali
Studies Of Damage Tolerance In Automated Fiber Placement Based Heterogeneous Meso-Architectured Carbon/ Epoxy Composite Laminates., Karan Kodagali
Theses and Dissertations
Traditional unidirectional (UD) carbon fiber-reinforced polymer matrix composites manufactured via automated fiber placement (AFP) are widely used in aerospace structures. While heterogeneous at the micro-scale, these materials are homogeneous at the meso-scale (ply-scale). The major limitation is its limited toughness, poor damage tolerance/impact resistance capability and the inability to sufficiently redistribute stresses, resulting in strength-toughness tradeoffs, making them susceptible to impact damage. From previous studies, there is an understanding that fiber architecture has a first order effect on the damage tolerance. Introducing new discontinuous/heterogeneous meso-scale architectures, through an optimal merger of material and structure, can result in unprecedented property improvements …
The Effect Of Through Thickness Reinforcement Angle On The Disbonding Behavior In Skin-Stringer Configuration, Christopher John Morris
The Effect Of Through Thickness Reinforcement Angle On The Disbonding Behavior In Skin-Stringer Configuration, Christopher John Morris
Mechanical & Aerospace Engineering Theses & Dissertations
Post-cure through thickness reinforcement is a method used to increase the mechanical properties of composite laminates in the transverse direction. This study conducted a test on skin-stringer structures bonded together in three configurations using an epoxy or thermoplastic adhesive at the interface with reinforcing pins inserted through the laminate thickness located at the edge of the stringer at differing angles between -30º and 30º. The fabrication of these samples in configurations B and C consisted of the use of carbon fiber prepeg laminate at a ply orientation of [02902]2s for the skin and [0 90] …
Investigation Of Fatigue Response With Analytical And Machine Learning Models And Hygroscopic Analysis Of Asymmetric Bistable Cfrp Composites, Shoab Ahmed Chowdhury
Investigation Of Fatigue Response With Analytical And Machine Learning Models And Hygroscopic Analysis Of Asymmetric Bistable Cfrp Composites, Shoab Ahmed Chowdhury
All Dissertations
Asymmetric bistable carbon fibre reinforced plastic (CFRP) composites enable a broad range of applications as they can sustain multiple stable configurations and have small snap-through load requirements. These unique features, coupled with their light strength-to-weight and stiffness-to-weight ratios, have made them preferred options for multifunctional systems. This study investigates the fatigue and hygroscopic response of 2-ply, [0/90] bistable CFRP laminates and proposes predictive modeling approaches for improved performance.
While previous studies widely researched and documented the fatigue of general composites in axial loading, fatigue analysis of asymmetric bistable composites in the out-of-plane snap-through direction is inadequate. This study performs fatigue …
Chemical And Physical Interaction Mechanisms And Multifunctional Properties Of Plant Based Graphene In Carbon Fiber Epoxy Composites, Daniel W. Mulqueen
Chemical And Physical Interaction Mechanisms And Multifunctional Properties Of Plant Based Graphene In Carbon Fiber Epoxy Composites, Daniel W. Mulqueen
Mechanical & Aerospace Engineering Theses & Dissertations
Graphene has generated substantial interest as a filler due to its exceptional strength, flexibility, and conductivity but faces obstacles in supply and implementation. A renewable, plant-based graphene nanoparticle (pGNP) presents a more accessible and sustainable filler with the same properties as mineral graphenes. In this study, the mechanisms of graphene reinforcement in carbon fiber reinforced plastic (CFRP) were examined, along with the resulting improvements to mechanical strength, resistance to crack propagation, electrical and thermal conductivity at elevated temperatures. pGNP, produced from renewable biomass, was shown to have a graphitic structure with flakes 3-10 layers thick and a median lateral size …
Northrop Grumman Collaboration Project, Nikkia Psomas-Sheridan, Santiago Robles, Ben Elkayam, Benjamin Ulfhake
Northrop Grumman Collaboration Project, Nikkia Psomas-Sheridan, Santiago Robles, Ben Elkayam, Benjamin Ulfhake
Mechanical Engineering
The Northrop Grumman Collaboration Project (NGCP) is a collaborative club project sponsored by Northrop Grumman for the students of Cal Poly San Luis Obispo (CPSLO) and Cal Poly Pomona (CPP) to create a fleet of vehicles to aid in the simulated rescue of stranded hiker. The CPSLO club is responsible for delivering an autonomous flight vehicle that can suppress a fire and retrieve a payload. Mechanical Design Team of the CPSLO team was responsible for the design of the frame, electronics housing, and payload and fire suppression systems.
The Modernization Of Large Power Transformer Tanks, Babajide O. Williams
The Modernization Of Large Power Transformer Tanks, Babajide O. Williams
Electronic Theses and Dissertations
Due to the current demands placed on the power grid in terms of climate change, increasing urbanization, and terrorist attacks, the U.S. government in response to these demands, mandated that all the grid components be modernized in order to increase their reliability. As a critical component of the grid, Large Power Transformers (LPTs) play a key role in ensuring sustainable power generation and distribution. A literature search performed in this work and the analysis of data retrieved from the search showed that the tanks of these LPTs are critical to their durability, longevity, and reliability. Therefore, the reliability of LPTs …
A Predictive Analysis Of The Influence Of Thickness And Length On The Curvature Of Square Bistable Carbon Fiber Reinforced Composite Laminates, Stephan Terry
All Theses
This thesis presents a predictive analysis of the stability of square bistable carbon fiber reinforced composite laminates under various loading conditions. The stability of these laminates is essential to their performance and longevity and is influenced by factors such as thickness and length. Analytical and numerical techniques are used to model the behavior of these laminates, and experimental tests are conducted to validate the models. The findings of this research have implications for the design and optimization of square bistable carbon fiber reinforced composites.
The study investigates the relationships between the side length and thickness of square laminates for bistability. …
Fatigue Performance Modeling In Advanced Out-Of-Autoclave Composites For Aerospace Applications, Grayson Reid Curry
Fatigue Performance Modeling In Advanced Out-Of-Autoclave Composites For Aerospace Applications, Grayson Reid Curry
Mechanical and Aerospace Engineering Theses
Increased application of composite materials in the military and civil applications renewed the interest to development of high-fidelity methodologies for predicting their performance characteristics. Besides the traditional autoclave processed structural composites such as IM7/8552 and IM7/977-3 widely used on various platforms, novel materials such IM7/5320-1 suitable for Out-of-Autoclave (OoA) cure became of interest. Static and fatigue performance prediction of Open-Hole quasi-isotropic laminates made from IM7/5320-1 was performed in this work by using the Finite Element Analysis software BSAM. Progressive failure simulation including delaminations, matrix cracks and fiber failure was performed. Regularized eXtended Finite Element Methods (RXFEM) was used for mesh …
Effects Of Metal Organic Frameworks In Polyether Block Amide Elastomer, Joe Alex
Effects Of Metal Organic Frameworks In Polyether Block Amide Elastomer, Joe Alex
Mechanical and Aerospace Engineering Theses
Metal-organic frameworks (MOFs) are highly porous materials that find extensive applications in gas absorption and separation in recent years. These hybrid materials can be designed with specific pore sizes and voids to selectively filter gases. PEBAX (MV 1074) is a commercially available polyether block amide copolymer generally used in gas separation applications. In this study, we characterize two different MOFs by means of a dispersion study and create a medium for them to be evenly dispersed into the aforementioned copolymer matrix. Polymer composite fibers are extruded using a twin-screw extruder and a winding unit at pre-determined parameters for winding speed …
Metal Fused Filament Fabrication: Distortion Compensation & Co2 Electrochemical Reduction, Jean Emmanuel Montes Ramirez
Metal Fused Filament Fabrication: Distortion Compensation & Co2 Electrochemical Reduction, Jean Emmanuel Montes Ramirez
Open Access Theses & Dissertations
Metal fused filament fabrication (MF3) is a rapidly growing additive manufacturing technology that enables the creation of complex metal parts with high accuracy and precision. Copper, a highly conductive metal with various applications in industries such as electronics and aerospace, is a promising material for MF3. In this study, we investigated the use of MF3 copper parts to fabricate copper electrodes for CO2 electrochemical reduction. We examined the post-processing manufacturing process of debinding and sintering to obtain fully 3D printed copper parts in an air environment. Our results demonstrate that MF3 copper parts have high porosity, providing a larger active …
Fusion Bonding Behavior Of 3d Printed Pa6/Cf Composites Via Post Fabrication Compaction, Gonzalo Fernandez Mediavilla
Fusion Bonding Behavior Of 3d Printed Pa6/Cf Composites Via Post Fabrication Compaction, Gonzalo Fernandez Mediavilla
Mechanical & Aerospace Engineering Theses & Dissertations
Additive manufacturing (AM) is becoming a robust production technology for aerospace, healthcare, and construction industries among others. Fused Deposition Modelling (FDM) is one of the methods most used to 3D print products. FDM has limitation due to interlayer adhesion and restriction imposed by the printing direction. Specially with AM composites, as reinforced nylon PA6 with short fibers, parts show more strength along the direction of the filament due to the alignment of the carbon fibers, but weaker in other directions. The proposed method to solve this issue is to print parts separately and join them together by fusion bonding. PA6/CF …
Shape Memory Polymer-Based Multifunctional Syntactic Foams, Siavash Sarrafan
Shape Memory Polymer-Based Multifunctional Syntactic Foams, Siavash Sarrafan
LSU Doctoral Dissertations
With the increase in popularity of shape memory polymers (SMPs), especially in applications such as aerospace, textile, biomedical engineering, and even structures, the weight of the material and the devices made with it has always been a crucial factor. Using the shape memory polymer as a matrix to make a syntactic foam is one of the best and most affordable approaches to creating a lighter material that still has the shape memory effect. The addition of particles of different stiffness, strength, and size, with variable fractions, creates a composite that enables engineering the mechanical, as well as other physical and …
Investigation Of Manufacturing Techniques For Magnetorheological Elastomers To Expand Feasibility In A Diverse Array Of Applications, Austin S. Robbins
Investigation Of Manufacturing Techniques For Magnetorheological Elastomers To Expand Feasibility In A Diverse Array Of Applications, Austin S. Robbins
Electronic Theses and 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 …
Northrop Grumman Collaboration Project, Nikkia Rae Psomas-Sheridan, Santiago Robles, Ben Elkayam, Benjamin Ulfhake
Northrop Grumman Collaboration Project, Nikkia Rae Psomas-Sheridan, Santiago Robles, Ben Elkayam, Benjamin Ulfhake
Mechanical Engineering
The Northrop Grumman Collaboration Project (NGCP) is a collaborative club project sponsored by Northrop Grumman for the students of Cal Poly San Luis Obispo (CPSLO) and Cal Poly Pomona (CPP) to create a fleet of vehicles to aid in the simulated rescue of stranded hiker. The CPSLO club is responsible for delivering an autonomous flight vehicle that can suppress a fire and retrieve a payload. Mechanical Design Team of the CPSLO team was responsible for the design of the frame, electronics housing, and payload and fire suppression systems.
Anisotropic Material Behavior Of 3d Printed Fiber Composites, Jordan Garcia
Anisotropic Material Behavior Of 3d Printed Fiber Composites, Jordan Garcia
Theses and Dissertations--Mechanical 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 …