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Articles 1 - 10 of 10
Full-Text Articles in Mechanical Engineering
Durability Of Vacuum Infusion Tooling Produced From Fused Granular Fabrication Additive Manufacturing, Nathan Northrup, Jason Weaver, Andy R. George
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
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 …
Using The Chloride Penetration Depth Obtained From Rcpt To Assess The Permeability Of Concrete, Kang-Shiun Huang, Chung-Chia Yang
Using The Chloride Penetration Depth Obtained From Rcpt To Assess The Permeability Of Concrete, Kang-Shiun Huang, Chung-Chia Yang
Journal of Marine Science and Technology
A review of the literature on the rapid chloride permeability test (RCPT; ASTM C1202) indicates that RCPT has a few shortcomings, namely complex anions in concrete and Joule heating. The charge passed through concrete is affected by chloride ions because of the complex anions in concrete. Moreover, Joule heating influences the experimental temperature and causes an abnormal increase in the charge passed. Engineers have focused on the advance of the critical chloride front toward steel, but the charge passed in RCPT experiments has a poor relationship with the chloride penetration depth in fly ash concrete. Thus, it is risky to …
Incorporation Of Silica Nanoparticles Into The Underlayer Of Pda/Ptfe Thin Coatings, Adedoyin Abe
Incorporation Of Silica Nanoparticles Into The Underlayer Of Pda/Ptfe Thin Coatings, Adedoyin Abe
Mechanical Engineering Undergraduate Honors Theses
Polytetrafluoroethylene (PTFE) is one of the most low friction and corrosion resistant solid lubricants. Prior studies have shown that a polydopamine (PDA) underlayer enhances the durability of PTFE thin coating. In this study, 100, 200, and 300 µL of aqueous silica nanoparticle (NP) solutions were added to the PDA deposition solution. The durability and coefficient of friction of PDA/PTFE thin coatings on stainless steel substrates are investigated with and without incorporating the silica NPs. The coatings were tested in dry contact conditions using a Universal Mechanical Tester (UMT) with a ball-on-flat configuration in a reciprocating motion. It was found that …
Behavior Of Eb Frp Masonry Bond Under Service Temperature, Zuhair Al-Aljaberi, John J. Myers, K. Chandrashekhara
Behavior Of Eb Frp Masonry Bond Under Service Temperature, Zuhair Al-Aljaberi, John J. Myers, K. Chandrashekhara
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The interest in advanced composites in repairing and strengthening infrastructure systems has considerably increased, especially as the application externally bonded (EB) fiber reinforced polymer (FRP) has become more well established. Previous research on bond behavior has focused on impact of durability by considering exposure to harsh environmental conditions and testing the specimens after exposure, rather than testing bond performance during exposure. The influence of directly applying temperature on bond behavior represents an open topic that needs to be investigated in more detail. This study is one of the first studies to investigate the bond behavior when the composite is subjected …
Effect Of Fly Ash Fortification In The Manufacture Process Of Making Concrete Towards Characteristics Of Concrete In Sulfuric Acid Solution, Asep Handaya Saputra, Muhammad Shohibi, Masatoshi Kubouchi
Effect Of Fly Ash Fortification In The Manufacture Process Of Making Concrete Towards Characteristics Of Concrete In Sulfuric Acid Solution, Asep Handaya Saputra, Muhammad Shohibi, Masatoshi Kubouchi
Makara Journal of Technology
Fly ash is a silica or alumino silica material that can be used as a constituent of cement in the concrete manufacturing process. Utilization of fly ash aims to improve durability and minimize the reduction of concrete’s compressive strength exposed to an acidic environment, which can be achieved through the pozzolanic reaction of fly ash with Ca(OH)2 within concrete. The reduced content of Ca(OH)2 through pozzolanic reaction will minimize the tendency of ettringite formation (compounds that cause deterioration and decrease the compressive strength of concrete). In order to determine the relation between fly ash replenishment into concrete with concrete’s characteristics …
Biodiesel Feasibility Study: An Evaluation Of Material Compatibility; Performance; Emission And Engine Durability
A.S. Md Abdul Haseeb
Biodiesel, derived from the transesterification of vegetable oils or animal fats, is composed of saturated and unsaturated long-chain fatty acid alkyl esters. In spite of having some application problems, recently it is being considered as one of the most promising alternative fuels in internal combustion engine. From scientific literatures, this paper has collected and analyzed the data on both advantages and disadvantages of biodiesel over conventional diesel. Since the aim of this study is to evaluate the biodiesel feasibility in automobiles, the first section is dedicated to materials compatibility in biodiesel as compared to that in diesel. The highest consensus …
High Strength And Light-Weight Materials Inspired By The Exoskeleton Of Arthropods, Anette M. Karlsson
High Strength And Light-Weight Materials Inspired By The Exoskeleton Of Arthropods, Anette M. Karlsson
Mechanical Engineering Faculty Publications
This work investigates the multiscaled structure and the constitutive behavior of the exoskeleton of arthropods (Japanese beetle) along with the response of biomimicked structures. Image analysis (SEM and TEM) revealed three load-bearing regions comprised of chitin-protein fiber layers orientated parallel to the cuticle surface. The chitin fibers in the exocuticle and mesocuticle are organized in a helicoidal structure (layers stacked with a small rotational angle relative to their adjacent layers). The endocuticle has a distinct pseudo-orthogonal pattern, characterized by a thin transitional helicoidal region inserted between two orthogonal layers. Idealized mechanics based models showed that the pseudo-orthogonal structure redistributes the …
Numerical Investigation Of Mechanical Durability In Polymer Electrolyte Membrane Fuel Cells, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson, Simon Cleghorn, William B. Johnson
Numerical Investigation Of Mechanical Durability In Polymer Electrolyte Membrane Fuel Cells, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson, Simon Cleghorn, William B. Johnson
Mechanical Engineering Faculty Publications
The relationship between the mechanical behavior and water transport in the membrane electrode assembly (MEA) is numerically investigated. Swelling plays a key role in the mechanical response of the MEA during fuel cell operation because swelling can be directly linked to the development of stresses. Thus, in the model introduced here, the stresses and the water distribution are coupled. Two membranes are studied: unreinforced perfluorosulfonic acid (PFSA) and an experimental reinforced composite membrane. The results suggest that open-circuit voltage operations lead to a uniform distribution of stresses and plastic deformation, whereas under current-load operation, the stresses and the plastic deformation …
Mechanical Properties And Durability Of A Composite Material At Cryogenic Temperatures, Ray Walton Grenoble
Mechanical Properties And Durability Of A Composite Material At Cryogenic Temperatures, Ray Walton Grenoble
Mechanical & Aerospace Engineering Theses & Dissertations
Several issues relevant to the use of a high-performance graphite-epoxy material in hydrogen storage tank applications have been examined. The tensile properties of IM7/977-2 were evaluated as a function of test temperature and thermal-mechanical load history. The temperature dependent coefficient of thermal expansion (CTE) of unidirectional specimens of the same material was measured between -200°C and 0°C. The effects of test temperature, mechanical loading, and damage state on the leak rate of hydrogen gas through IM7/977-2 laminates were evaluated using a novel test system. Finally, the mechanical properties of several commercially available polymer films, which might prove useful as leak-resistant …