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2019

Mechanical properties

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Articles 1 - 13 of 13

Full-Text Articles in Engineering

Design Of High-Strength Refractory Complex Solid-Solution Alloys, Prashant Singh, Aayush Sharma, Andrei V. Smirnov, Mouhamad S. Diallo, Pratik K. Ray, Ganesh Balasubramanian, Duane D. Johnson Aug 2019

Design Of High-Strength Refractory Complex Solid-Solution Alloys, Prashant Singh, Aayush Sharma, Andrei V. Smirnov, Mouhamad S. Diallo, Pratik K. Ray, Ganesh Balasubramanian, Duane D. Johnson

Ganesh Balasubramanian

Nickel-based superalloys and near-equiatomic high-entropy alloys containing molybdenum are known for higher temperature strength and corrosion resistance. Yet, complex solid-solution alloys offer a huge design space to tune for optimal properties at slightly reduced entropy. For refractory Mo-W-Ta-Ti-Zr, we showcase KKR electronic structure methods via the coherent-potential approximation to identify alloys over five-dimensional design space with improved mechanical properties and necessary global (formation enthalpy) and local (short-range order) stability. Deformation is modeled with classical molecular dynamic simulations, validated from our first-principle data. We predict complex solid-solution alloys of improved stability with greatly enhanced modulus of elasticity (3× at 300 K ...


Spiderworms: Using Silkworms As Hosts To Produce A Hybrid Silkworm-Spider Silk Fiber, Ana Laura Licon Aug 2019

Spiderworms: Using Silkworms As Hosts To Produce A Hybrid Silkworm-Spider Silk Fiber, Ana Laura Licon

All Graduate Theses and Dissertations

Spider silk has received significant attention due to its fascinating mechanical properties. Given the solitary and cannibalistic behavior of spiders, spider silk farming is impractical. Unlike spiders, silkworms are capable of producing large quantities of a fibrous product in a manner mimetic to spiders, and there already exists an industry to process cocoons into threads and textiles for many applications. The combination of silk farming (sericulture), a millennia old practice, and modern advancements in genetic engineering has given rise to an innovative biomaterial inspired by nature; transgenic silkworm silk.

This project focuses on the creation of chimeric silkworm-spider silk fibers ...


Investigation Of Nondestructive Testing Methods For Friction Stir Welding, Hossein Taheri, Margaret Kilpatrick, Matthew Norvalls, Warren Harper, Lucas Koester, Timothy Bigelow, Leonard J. Bond May 2019

Investigation Of Nondestructive Testing Methods For Friction Stir Welding, Hossein Taheri, Margaret Kilpatrick, Matthew Norvalls, Warren Harper, Lucas Koester, Timothy Bigelow, Leonard J. Bond

Electrical and Computer Engineering Publications

Friction stir welding is a method of materials processing that enables the joining of similar and dissimilar materials. The process, as originally designed by The Welding Institute (TWI), provides a unique approach to manufacturing—where materials can be joined in many designs and still retain mechanical properties that are similar to, or greater than, other forms of welding. This process is not free of defects that can alter, limit, and occasionally render the resulting weld unusable. Most common amongst these defects are kissing bonds, wormholes and cracks that are often hidden from visual inspection. To identify these defects, various nondestructive ...


Predicting The Mechanical Properties Of Nanocomposites Reinforced With 1-D, 2-D And 3-D Nanomaterials, Scott Edward Muller May 2019

Predicting The Mechanical Properties Of Nanocomposites Reinforced With 1-D, 2-D And 3-D Nanomaterials, Scott Edward Muller

Theses and Dissertations

Materials with features at the nanoscale can provide unique mechanical properties and increased functionality when included as part of a nanocomposite. This dissertation utilizes computational methods at multiple scales, including molecular dynamics (MD) and density functional theory (DFT), and the coupled atomistic and discrete dislocation multiscale method (CADD), to predict the mechanical properties of nanocomposites possessing nanomaterials that are either 1-D (carbyne chains), 2-D (graphene sheets), or 3-D (Al/amorphous-Si core-shell nanorod).

The MD method is used to model Ni-graphene nanocomposites. The strength of a Ni-graphene nanocomposite is found to improve by increasing the gap between the graphene sheet and ...


Influence Of Mechanical Properties Of Paper Coating On The Crack At The Fold Problem, Seyyed Mohammad Hashemi Najafi May 2019

Influence Of Mechanical Properties Of Paper Coating On The Crack At The Fold Problem, Seyyed Mohammad Hashemi Najafi

Electronic Theses and Dissertations

Paper coating layers are subject to various stresses and deformations in many converting processes such as calendering, printing, slitting, and folding of the paper. In some cases, products may crack during folding to generate a defect called cracking at the fold (CAF). The parameters that influence these defects are not well understood. The overall goal of this thesis is to better understand the CAF behavior as related to material properties of the coating layer.

A method was developed to produce free-standing pigmented coating layers thick enough to be tested in bending as well as tension. The mechanical properties of these ...


Tissue Equivalent Gellan Gum Gel Materials For Clinical Mri And Radiation Dosimetry, Pawel Brzozowski Apr 2019

Tissue Equivalent Gellan Gum Gel Materials For Clinical Mri And Radiation Dosimetry, Pawel Brzozowski

Electronic Thesis and Dissertation Repository

Hydrogels contain high amount of water allowing their use as surrogates to human tissues with specific properties that can be tuned by additives. Gellan gum is a gel-forming material of interest and is a replacement for other common gelling agent with limited use as a tissue phantom. Therefore, this thesis examines the application of gellan gum gels as a novel magnetic resonance imaging (MRI) phantom with a design of experiments model to obtain tunable properties. The analysis was extended to include mechanical and electrical properties with a separate design of experiment. Gels doped with synthesized superparamagnetic iron oxide nanoparticles (SPIONs ...


The Effect Of Fine And Coarse Recycled Aggregates On Fresh And Mechanical Properties Of Self-Compacting Concrete, Mahmoud Nili, Hossein Sasanipour, Farhad Aslani Apr 2019

The Effect Of Fine And Coarse Recycled Aggregates On Fresh And Mechanical Properties Of Self-Compacting Concrete, Mahmoud Nili, Hossein Sasanipour, Farhad Aslani

ECU Publications Post 2013

Today, the use of recycled aggregates as a substitute for a part of the natural aggregates in concrete production is increasing. This approach is essential because the resources for natural aggregates are decreasing in the world. In the present study, the effects of recycled concrete aggregates as a partial replacement for fine (by 50%) and coarse aggregates (by 100%) were examined in the self-compacting concrete mixtures which contain air-entraining agents and silica fumes. Two series of self-compacting concrete mixes have been prepared. In the first series, fine and coarse recycled mixtures respectively with 50% and 100% replacement with air entraining ...


Development Of Heavyweight Self-Compacting Concrete And Ambient-Cured Heavyweight Geopolymer Concrete Using Magnetite Aggregates, Afsaneh Valizadeh, Farhad Aslani, Zohaib Asif, Matt Roso Mar 2019

Development Of Heavyweight Self-Compacting Concrete And Ambient-Cured Heavyweight Geopolymer Concrete Using Magnetite Aggregates, Afsaneh Valizadeh, Farhad Aslani, Zohaib Asif, Matt Roso

ECU Publications Post 2013

Heavyweight self-compacting concrete (HWSCC) and heavyweight geopolymer concrete (HWGC) are new types of concrete that integrate the advantages of heavyweight concrete (HWC) with self-compacting concrete (SCC) and geopolymer concrete (GC), respectively. The replacement of natural coarse aggregates with magnetite aggregates in control SCC and control GC at volume ratios of 50%, 75%, and 100% was considered in this study to obtain heavyweight concrete classifications, according to British standards, which provide proper protection from sources that emit harmful radiations in medical and nuclear industries and may also be used in many offshore structures. The main aim of this study is to ...


An Investigation Of The Effect Of Direct Metal Deposition Parameters On The Characteristics Of The Deposited Layers, Tarak A. Amine, Joseph William Newkirk, Frank W. Liou Jan 2019

An Investigation Of The Effect Of Direct Metal Deposition Parameters On The Characteristics Of The Deposited Layers, Tarak A. Amine, Joseph William Newkirk, Frank W. Liou

Frank W. Liou

Multilayer direct laser deposition (DLD) is a fabrication process through which parts are fabricated by creating a molten pool into which metal powder is injected as particles. During fabrication, complex thermal activity occurs in different regions of the build; for example, newly deposited layers will reheat previously deposited layers. The objective of this study was to provide insight into the thermal activity that occurs during the DLD process. This work focused on the effect of the laser parameters of newly deposited layers on the microstructure and mechanical properties of the previously deposited layers in order to characterize these effects to ...


Development Of Cardanol-Based Epoxy Coating, Nicholas Pottschmidt Jan 2019

Development Of Cardanol-Based Epoxy Coating, Nicholas Pottschmidt

Williams Honors College, Honors Research Projects

The purpose of this project was to determine the suitability of cardanol glycidyl ether (CGE) as a substitute for trimethylolpropane triglycidyl ether (TMPGE) as the reactive diluent in epoxy coatings. CGE may be a naturally-derived alternative to TMPGE, which is a commonly-used petroleum-derived reactive diluent. Epoxy coatings were formulated with CGE replacing increasing amounts of TMPGE in the formulation. Corrosion protection provided by the coatings was evaluated with electrochemical impedance spectroscopy (EIS). Mechanical properties of the coatings (hardness, flexibility, adhesion, and impact resistance) were evaluated with applicable ASTM standards.

EIS results revealed the coating formulated with only CGE had superior ...


Increasing Mechanical Properties Of A Double Network Hydrogel From Polyacrylamide And Agar With Methylenebisacrylamide As A Photocrosslinker, Madelyn Jeske Jan 2019

Increasing Mechanical Properties Of A Double Network Hydrogel From Polyacrylamide And Agar With Methylenebisacrylamide As A Photocrosslinker, Madelyn Jeske

Williams Honors College, Honors Research Projects

Double Network hydrogels are three dimensional networks of a soft, mechanically tough material that have been used for drug delivery, agriculture, adhesives, and other widely applicable uses. Using the one-pot method, a single hydrogel can be produced in 3 hours as opposed to the once demonstrated three days. It has been found that with a first, physically cross linked network and a second, chemically cross linked, hybrid double network hydrogels exhibit high mechanical properties and are freeshapeable. Agar is a thermoreversible organic molecule with a triple helix structure that provides an excellent first network that organizes into aggregate bundles once ...


Mechanical Characterizations Of 3d-Printed Plla/Steel Particle Composites, Hozhabr Mozafari, Pengfei Dong, Haitham Hadidi, Michael P. Sealy, Linxia Gu Jan 2019

Mechanical Characterizations Of 3d-Printed Plla/Steel Particle Composites, Hozhabr Mozafari, Pengfei Dong, Haitham Hadidi, Michael P. Sealy, Linxia Gu

Mechanical & Materials Engineering Faculty Publications

The objective of this study is to characterize the micromechanical properties of poly-L-lactic acid (PLLA) composites reinforced by grade 420 stainless steel (SS) particles with a specific focus on the interphase properties. The specimens were manufactured using 3D printing techniques due to its many benefits, including high accuracy, cost effectiveness and customized geometry. The adopted fused filament fabrication resulted in a thin interphase layer with an average thickness of 3 μm. The mechanical properties of each phase, as well as the interphase, were characterized by nanoindentation tests. The effect of matrix degradation, i.e., imperfect bonding, on the elastic modulus ...


Fire Performance Of Heavyweight Self-Compacting Concrete And Heavyweight High Strength Concrete, Farhad Aslani, Fatemeh Hamidi, Qilong Ma Jan 2019

Fire Performance Of Heavyweight Self-Compacting Concrete And Heavyweight High Strength Concrete, Farhad Aslani, Fatemeh Hamidi, Qilong Ma

ECU Publications Post 2013

In this study, the fresh and hardened state properties of heavyweight self-compacting concrete (HWSCC) and heavyweight high strength concrete (HWHSC) containing heavyweight magnetite aggregate with 50, 75, and 100% replacement ratio, and their performance at elevated temperatures were explored experimentally. For fresh-state properties, the flowability and passing ability of HWSCCs were assessed by using slump flow, T500 mm, and J-ring tests. Hardened-state properties including hardened density, compressive strength, and modulus of elasticity were evaluated after 28 days of mixing. High-temperature tests were also performed to study the mass loss, spalling of HWSCC and HWHSC, and residual mechanical properties at 100 ...