Development Of Hybrid Ultra-High Performance Concrete Thermoplastic Composite Panels For Blast And Ballistic Protection, Alyssa M. Libby
Electronic Theses and Dissertations
In recent years, ultra-high performance concrete (UHPC) has become a material of interest for structures needing resistance to impact and blast loadings. These types of loadings have induced brittle flexural failure in UHPC due to punching shear from the impactor. One way to improve the impact resistance, energy absorption, and ductility of UHPC is by adding fiber-reinforced polymer (FRP) skins to the front and rear faces of the concrete, resulting in a sandwich configuration. In this study, E-glass fiber-reinforced thermoplastic laminates were bonded to UHPC panels using a heated consolidation process known as stamp thermoforming. The bond between the UHPC ...
Finite Element Analysis Of Impact Resistant Composites Inspired By Peacock Mantis Shrimp, 2021 University of Southern Maine
Finite Element Analysis Of Impact Resistant Composites Inspired By Peacock Mantis Shrimp, Nandati Shrestha
Thinking Matters Symposium
The fist-like club of the peacock mantis shrimp, a 5-inch marine crustacean, can strike its prey with speed faster than a .22-caliber bullet with an impact force more than 1,000 times its own weight. Although these creatures punch so fast that it even boils the water, they don’t take any damage. This incredible insusceptibility is due to the arrangement of mineralized fiber layers in which each fibrous layer is laid at a slightly rotated angle to form a helicoidal structure that acts as a shock absorber for the club. The goal is to perform a finite element analysis ...
Influence Of Parameters Of Non-Standard Modes Of Heat Treatment On Increasing The Wear Resistance Of Steel Products, 2021 ashkent state technical University, the department “Metal Forming”
Influence Of Parameters Of Non-Standard Modes Of Heat Treatment On Increasing The Wear Resistance Of Steel Products, Dorob Murotovich Berdiyev Dsn, Abdulaziz Abdullajanovich Yusupov Head Teacher, Ravshan Kobilovich Tashmatov Doctoral Student, Tuychi Nemat Ogli Ibodullayev Assistant, Kabira Erkinovna Qurbonova Head Teacher
The use of non-standard modes of heat treatment increases the density of dislocations in the crystal structure of the α-phase and increases the wear resistance of carbon, low-alloy steels under various friction conditions, which is comparable to the results when heated to a standard temperature (Ac3+30÷50 °C). The preliminary extreme heating temperature is determined. After re-quenching at standard temperature and low tempering, the wear resistance of steels under various types of friction increases by up to 40 % compared to standard quenching.
Study Of Laser Based Additive Manufacturing For Titanium And Copper Alloys, 2021 Louisiana State University
Study Of Laser Based Additive Manufacturing For Titanium And Copper Alloys, Congyuan Zeng
LSU Doctoral Dissertations
Material processing by laser is increasingly applied in industrial applications for its outstanding characteristics, such as localized heating, high efficiency, and high manufacturing precision. In this study, two kinds of laser material processing strategies were investigated, namely laser surface engineering and laser-powder-bed fusion additive manufacturing, with pure titanium and copper alloys as target materials, respectively.
For laser surface engineering related studies, the work includes the investigation of the dynamic interactions between titanium and pure nitrogen or ambient air under transient laser processing conditions. Thanks to the in-situ synchrotron X-ray diffraction tests, the high-temperature reaction steps between titanium and pure nitrogen ...
Initial Assessment Of Liquefied Scrap Tire Concrete, 2021 Intertek-PSI
Initial Assessment Of Liquefied Scrap Tire Concrete, Abdulkareem Kuaryouti, Christopher D. Eamon
Civil and Environmental Engineering Faculty Research Publications
A new approach to incorporate scrap tire material into concrete was investigated, where two reclaimed waste tire components, carbon black and fuel oil, were used to replace a portion of water. The effect of “liquid tire” content to water ratios from 5-40% on an otherwise typical concrete mix were assessed, where compressive and flexural strength, flexural toughness, modulus of elasticity, and several fresh concrete properties were determined. Results were compared to typically expected results of traditional shredded tire mixes with equivalent tire content. It was found that the liquid tire mixes experienced significantly less losses of compressive strength and workability ...
Design Of High Stability Superhydrophobic Surfaces, 2021 University of Windsor
Design Of High Stability Superhydrophobic Surfaces, Shuo Wang
In the recent two decades, superhydrophobic surfaces' properties and their potential applications have attracted much attention. With the main advantages of self-cleaning, anti-icing, and drag-reduction, the superhydrophobic surfaces can be applied to many industry fields. But the traditional fabrication methods developed in the last twenty years for the superhydrophobic surfaces were focusing on mimicking nature. Specifically, most of the fabrication methods were based on the micro, and nano-scale structure of plants and animals, which came with the problems that such weeny structure on the surfaces would be damaged easily in the practical application without the self-healing capability like the creatures ...
Structural Identification And Damage Detection In Bridges Using Wave Method And Uniform Shear Beam Models: A Feasibility Study, 2021 California State University, Long Beach
Structural Identification And Damage Detection In Bridges Using Wave Method And Uniform Shear Beam Models: A Feasibility Study, Mehran Rahmani, Manan Naik
Mineta Transportation Institute Publications
This report presents a wave method to be used for the structural identification and damage detection of structural components in bridges, e.g., bridge piers. This method has proven to be promising when applied to real structures and large amplitude responses in buildings (e.g., mid-rise and high-rise buildings). This study is the first application of the method to damaged bridge structures. The bridge identification was performed using wave propagation in a simple uniform shear beam model. The method identifies a wave velocity for the structure by fitting an equivalent uniform shear beam model to the impulse response functions of ...
Research Trend Of Metal Matrix Composites Reinforced With Silica Extracted By Green Route: A Bibliometric Analysis, 2021 Symbiosis Institute of Technology (SIT), Symbiosis International (Deemed University) (SIU), Lavale, Pune, India
Research Trend Of Metal Matrix Composites Reinforced With Silica Extracted By Green Route: A Bibliometric Analysis, Rinku Datkhile, Meena Laad, Babaji Ghule
Library Philosophy and Practice (e-journal)
Metal Matrix Composites have acquired an important place in the engineering applications due to their distinctive characteristics such as high specific strength, lower specific gravity, improved material stiffness, better durability, enhanced creep and fatigue strength etc. Worldwide scientists are working on the improvement of mechanical properties of composite materials. The present work attempts to summarise all the research carried out on metal matrix composites reinforced with silica extracted by green route and provides up-to-date research material for researchers who are interested in the field of composites with metal matrices. Scopus databases and software such as Gephi Vos Viewer and Table2Net ...
Atmospheric Corrosion Of Galvanically Coupled Aluminum Alloys And Carbon Steel, 2021 The University of Akron
Atmospheric Corrosion Of Galvanically Coupled Aluminum Alloys And Carbon Steel, Mitchell Felde
Williams Honors College, Honors Research Projects
Aluminum alloys are a steadily growing material being commonly used in lieu of typical steels. Additional alloying, heat treatment, and other property enhancing processes are expanding the use of these alloys. However, with this expansion, galvanic corrosion is becoming more of an issue in the design stage due to the combination of these alloys with steels. The automotive industry is one industry where the use of aluminum alloys is becoming common practice. Aluminum alloys provide a lightweight aspect over the conventional carbon steel that was used previously. As a result of this transition towards more lightweight materials, galvanic coupling is ...
Application Of Laser Assisted Ultrasonic Nanocrystal Surface Modification On Aluminum And 3d Printed Titanium, 2021 The University of Akron
Application Of Laser Assisted Ultrasonic Nanocrystal Surface Modification On Aluminum And 3d Printed Titanium, Eman Hassan, Thomas Crouse
Williams Honors College, Honors Research Projects
A novel surface treatment, laser assisted ultrasonic nanocrystal surface modification (LA-UNSM), has proved effective in increasing surface hardness, and fatigue life. The objective of this research is to determine the effectiveness of this process on components created with additive manufacturing. To accomplish this, we investigated the effectiveness of LA-UNSM treatment on aluminum, a common 3d printed metal, and the effectiveness of LA-UNSM processing on 3d printed titanium. We first conducted our own literature review to assess the practicality of using this same treatment on aluminum. We then treated traditionally manufactured aluminum at varying levels of laser intensity to determine if ...
Effect Of Applied Pressure During Sintering On The Densification And Mechanical Properties Of Sicf/Sic Composites Prepared By Electrophoretic Infiltration, 2020 1. Nano Center Indonesia, Banten 15314, Indonesia 2. Department of Mechanical Engineering, Universitas Mercu Buana, Jakarta 11650, Indonesia
Effect Of Applied Pressure During Sintering On The Densification And Mechanical Properties Of Sicf/Sic Composites Prepared By Electrophoretic Infiltration, Alfian Noviyanto
Makara Journal of Science
SiC-fiber-reinforced SiC matrix ceramic (SiCf/SiC) composites were successfully fabricated by electrophoretic infiltration and sintering at various applied pressures. The effect of applied pressure (i.e., 5, 10, and 20 MPa) was thoroughly examined, and applied pressure appears to influence the densification and mechanical properties of SiCf/SiC composites. The densities of SiCf/SiC composites prepared at applied pressure of 5, 10, and 20 MPa were 2.99, 3.10, and 3.16 g/cm3, respectively. All samples showed dense microstructures in their matrix areas; however, many closed pores were found with increasing pressure. Pressure induced ...
Laboratory Testing And Mechanistic Analysis Of Treated Subgrade Soils, 2020 University of Texas at Tyler
Laboratory Testing And Mechanistic Analysis Of Treated Subgrade Soils, Hari Kumar Reddy Yarrapureddi
Civil Engineering Theses
Calcium-based stabilizing agents such as cement and lime have been extensively used to improve the engineering properties of base and subgrade layers of pavement systems. Recently, polymers and chemical stabilizers have become popular due to cost efficiency, ease of application, and fast curing times. In this study, California Bearing Ratio (CBR) values of polymer and chemical treated soils were compared with the CBR values of soils treated with conventional stabilizers. Parametric sensitivity analyses was carried out on key parameters including the type of subgrade soil, stabilizing agent, stabilizing agent treatment levels, and moisture conditioning. Additionally, numerical analyses was performed to ...
Large Displacement J-Integral Double Cantilever Beam (Dcb) Test Method For Mode I Fracture Toughness, 2020 Boise State University
Large Displacement J-Integral Double Cantilever Beam (Dcb) Test Method For Mode I Fracture Toughness, Joshua Gunderson
Boise State University Theses and Dissertations
The J-integral is used to develop an alternative double cantilever beam (DCB) test method for the Mode I fracture toughness suitable for both small and large displacements. The current focus is the experimental determination of the Mode I interlaminar fracture toughness of composite materials, but the method is generally applicable to other similar tests and material systems, such as to the Mode I fracture toughness of adhesives. A series of five identical specimens are tested to compare the linear-elastic fracture mechanics method recommended by ASTM, which makes use of linear beam theory with root rotation, large displacement, and end ...
Defect Evolution In High-Temperature Irradiated Nuclear Graphite, 2020 Boise State University
Defect Evolution In High-Temperature Irradiated Nuclear Graphite, Steve Johns
Boise State University Theses and Dissertations
Graphite has historically been used as a moderator material in nuclear reactor designs dating back to the first man-made nuclear reactor to achieve criticality (Chicago Pile 1) in 1942. Additionally, graphite is a candidate material for use in the future envisioned next-generation nuclear reactors (Gen IV); specifically, the molten-salt-cooled (MSR) and very-high-temperature reactor (VHTR) concepts. Gen IV reactor concepts will introduce material challenges as temperature regimes and reactor lifetimes are anticipated to far exceed those of earlier reactors. Irradiation-induced defect evolution is a fundamental response in nuclear graphite subjected to irradiation. These defects directly influence the many property changes of ...
3-D Fabry–Pérot Cavities Sculpted On Fiber Tips Using A Multiphoton Polymerization Process, 2020 Air Force Institute of Technology
3-D Fabry–Pérot Cavities Sculpted On Fiber Tips Using A Multiphoton Polymerization Process, Jonathan W. Smith, Jeremiah C. Williams, Joseph S. Suelzer, Nicholas G. Usechak, Hengky Chandrahalim
This paper presents 3-D Fabry–Pérot (FP) cavities fabricated directly onto cleaved ends of low-loss optical fibers by a two-photon polymerization (2PP) process. This fabrication technique is quick, simple, and inexpensive compared to planar microfabrication processes, which enables rapid prototyping and the ability to adapt to new requirements. These devices also utilize true 3-D design freedom, facilitating the realization of microscale optical elements with challenging geometries. Three different device types were fabricated and evaluated: an unreleased single-cavity device, a released dual-cavity device, and a released hemispherical mirror dual-cavity device. Each iteration improved the quality of the FP cavity's reflection ...
Leveraging Biomimicry And Additive Manufacturing To Improve Load Transfer In Brittle Materials, 2020 University of Arkansas, Fayetteville
Leveraging Biomimicry And Additive Manufacturing To Improve Load Transfer In Brittle Materials, Ana Paula Bernardo
Theses and Dissertations
With the emergence of Additive Manufacturing (i.e., 3D printing) in construction, new strategically designed shapes can be created to improve load transfer through structural members and foundations. Cross-sections can be optimized to carry load using less material, or even using weaker constituent materials, like soils, which are cheap and abundant. The goal of this research is to investigate the benefits of using cellular patterns which leverage biomimicry in civil engineering applications, since nature has perfectly engineered materials and patterns which carry loads with the least amount of material possible. Most of the periodic cellular work to date has focused ...
An Investigation Into The Effects Of Fly Ash On Freeze-Thaw Durability Prediction, 2020 University of Arkansas, Fayetteville
An Investigation Into The Effects Of Fly Ash On Freeze-Thaw Durability Prediction, Yancy Schrader
Theses and Dissertations
Air is purposefully entrained into concrete primarily to improve resistance to freeze-thaw deterioration while saturated with water. Air entraining admixtures (AEAs) are chemical admixtures designed to entrain air into the concrete to provide adequate resistance to the effects of freezing and thawing. One of the challenges associated with air entrainment in concrete is the interaction of an AEA with supplementary cementitious materials present in the concrete, particularly fly ash. Fly ash is a by-product of the coal fired electrical generation industry, and often contains residual unburned carbon and other components that can increase the AEA demand of a particular concrete ...
Effect Of Citric Acid On Slump, Compressive Strength, And Setting Time Of Belitic Calcium Sulfoaluminate Concrete, 2020 University of Arkansas, Fayetteville
Effect Of Citric Acid On Slump, Compressive Strength, And Setting Time Of Belitic Calcium Sulfoaluminate Concrete, Israel Aguilar Rosero
Theses and Dissertations
Belitic calcium sulfoaluminate (BCSA) cement has well established advantages related to fast setting time, fast strength gain, long-term strengths, shrinkage, and sustainability. Due to its fast setting and hardening, this type of cement has historically been used to repair concrete structures, highways, and runways. This work provides much needed guidance on establishing mix design criteria for BCSA cement. Guidance is also given on the effects of set retarders on strength, slump, and setting times. Citric acid and a phosphonic acid-based admixture were tested as retarders for different concrete mixtures. Three studies were performed. In the slump study five different water ...
Fast Inverse Design Of Microstructures Via Generative Invariance Networks, 2020 Iowa State University
Fast Inverse Design Of Microstructures Via Generative Invariance Networks, Xian Yeow Lee, Joshua R. Waite, Chih-Hsuan Yang, Balaji Sesha Sarath Pokuri, Ameya Joshi, Aditya Balu, Chinmay Hegde, Baskar Ganapathysubramanian, Soumik Sarkar
Mechanical Engineering Publications
The problem of efficient design of material microstructures exhibiting desired properties spans a variety of engineering and science applications. An ability to rapidly generate microstructures that exhibit user-specified property distributions transforms the iterative process of traditional microstructure-sensitive design. We reformulate the microstructure design process as a constrained Generative Adversarial Network (GAN). This approach explicitly encodes invariance constraints within a GAN to generate two-phase morphologies for photovoltaic applications obeying design specifications: specifically, various short circuit current density and fill-factor combinations. Such invariance constraints can be represented by deep learning-based surrogates of full physics models mapping microstructure to photovoltaic properties. To circumvent ...
Ti-6al-4v Microstructural Orientation At Different Length Scales As A Function Of Scanning Strategies In Electron Beam Melting In Additive Manufacturing, Priyanka Agrawal, Maria J. Quintana, Matthew Kenney, Sabina Kumar, Alec Saville, Amy Clarke, Peter C. Collins
Materials Science and Engineering Conference Papers, Posters and Presentations
Additive manufacturing has been around for many years, yet the underlying physics of thermal gradients, local pressure environment, and other non-steady state manufacturing conditions are not fully understood. A Multi-University Research Initiative (MURI) is currently ongoing to measure liquid/solid and solid/solid interface stabilities in AM Ti-6Al-4V. Samples were produced with different beamscanning strategies in order to study the role of thermal gradients on the resulting microstructure. The motivation is to determine which beam-scanning strategy leads to desired grain size and texture. Orientation at different length scales (from mm to nm) can be quantified and compared with a combination ...