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Full-Text Articles in Engineering

Optimal Level Of Woody Biomass Co-Firing With Coal Power Plant Considering Advanced Feedstock Logistics System, Sangpil Ko, Pasi T. Lautala May 2018

Optimal Level Of Woody Biomass Co-Firing With Coal Power Plant Considering Advanced Feedstock Logistics System, Sangpil Ko, Pasi T. Lautala

Michigan Tech Publications, Part 1

Co-firing from woody biomass feedstock is one of the alternatives toward increased use of renewable feedstock in existing coal power plants. However, the economic level of co-firing at a particular power plant depends on several site-specific factors. Torrefaction has been identified recently as a promising biomass pretreatment option to lead to reduction of the feedstock delivered cost, and thus facilitate an increase in the co-firing ratio. In this study, a mixed integer linear program (MILP) is developed to integrate supply chain of co-firing and torrefaction process and find the optimal level of biomass co-firing in terms of minimized transportation and …


Application Of Microwave And Ultrasonic Techniques For Defect Detection In Pipes, Wissam Muzher Alobaidi May 2018

Application Of Microwave And Ultrasonic Techniques For Defect Detection In Pipes, Wissam Muzher Alobaidi

Theses and Dissertations

Microwaves promulgate through a waveguide, reflecting off its inner surface, of course. It is known that any irregularity (discontinuity) in the surface will alter the course of the reflected signal, and that the reflected signal can be recaptured and processed algorithmically to generate a waveform characteristic of the discontinuity. The work of this dissertation is based in this phenomenon. The aim is to develop methods for detecting and then characterizing pipe wall thinning (PWT) discontinuities in pipes. The work includes both simulations and practical experiments. New possibilities were discovered as the work progressed. Prior work revealed a promising initial setup …


A Biodegradable Piezoelectric Composite Scaffold Containing Zinc Oxide For Cartilage Repair Applications, Ateka Mohd Arabi Khader May 2018

A Biodegradable Piezoelectric Composite Scaffold Containing Zinc Oxide For Cartilage Repair Applications, Ateka Mohd Arabi Khader

Dissertations

Osteoarthritis (OA) affects 27 million adults in the United States. OA causes degeneration of articular cartilage and subchondral bone. Articular cartilage has limited ability to regenerate and repair. Bone and cartilage tissues have known piezoelectric properties, which means they can generate electrical activity in response to mechanical deformation. Using a biomimetic approach, zinc oxide (ZnO), which has known piezoelectric properties, is fabricated into a flexible three-dimensional fibrous scaffold by embedding ZnO nanoparticles into slow degrading polycaprolactone (PCL). Zinc ions can be released from the fibrous scaffold over time, which also may be beneficial for cell function since zinc has well-known …


Micronized Dry Drug Powder-Loaded Polymer Films For Delivery Of Poorly Water Soluble Drugs, Lu Zhang May 2018

Micronized Dry Drug Powder-Loaded Polymer Films For Delivery Of Poorly Water Soluble Drugs, Lu Zhang

Dissertations

Polymer strip films have been recently established as a robust platform for delivery of poorly water-soluble drugs via slurry casting, in particular using stable drug nanosuspensions. In this dissertation, a simpler, economically feasible, and robust method to directly incorporate dry micronized poorly water-soluble drug is introduced. As a major novelty, simultaneous surface modification using hydrophilic silica along with micronization is done using fluid energy mill (FEM) in order to reduce the hydrophobicity and agglomeration of poorly water-solube drug powder. When micronized coated drug powders are used, films exhibit improved appearance (thickness uniformity, visible lumps), better drug content uniformity (relative standard …


Halal Certification For An Industrial Machine Intended To Come In Contact With Food, Luca Caffarelli May 2018

Halal Certification For An Industrial Machine Intended To Come In Contact With Food, Luca Caffarelli

Theses

Halal Certification is a worldwide recognition that the products are permissible under Islamic law. These products are thus edible, drinkable or usable by Muslims. It can be extended to industrial machinery and tools. This Certification must be issued by a Notified Body under the supervision of an IMAM. Focus of the Certification are GMPs and Food Contact Materials and Articles. Four main phases to achieve Certification (the scheme is the same of ISO 14001, ISO 18001 and ISO 9001):

  • Pre-Audit - The activity is to evaluate the documentation describing our internal system.
  • Audit - The activity is to evaluate how …


Do Nir Spectra Collected From Laboratory-Reared Mosquitoes Differ From Those Collected From Wild Mosquitoes?, Masabho Peter Milali, Maggy T. Sikulu-Lord, Samson Sifael Kiware, Floyd E. Dowell, Richard J. Povinelli, George F. Corliss May 2018

Do Nir Spectra Collected From Laboratory-Reared Mosquitoes Differ From Those Collected From Wild Mosquitoes?, Masabho Peter Milali, Maggy T. Sikulu-Lord, Samson Sifael Kiware, Floyd E. Dowell, Richard J. Povinelli, George F. Corliss

Electrical and Computer Engineering Faculty Research and Publications

Background

Near infrared spectroscopy (NIRS) is a high throughput technique that measures absorbance of specific wavelengths of light by biological samples and uses this information to classify the age of lab-reared mosquitoes as younger or older than seven days with an average accuracy greater than 80%. For NIRS to estimate ages of wild mosquitoes, a sample of wild mosquitoes with known age in days would be required to train and test the model. Mark-release-recapture is the most reliable method to produce wild-caught mosquitoes of known age in days. However, it is logistically demanding, time inefficient, subject to low recapture rates, …


Elucidating The Action Of A Regulatory Lipid Ligand Via Molecular Simulation: Cholesterol Swarms And The Inwardly Rectifying Potassium Channel, Belinda Akpa, Nicolas Barbera, Irena Levitan May 2018

Elucidating The Action Of A Regulatory Lipid Ligand Via Molecular Simulation: Cholesterol Swarms And The Inwardly Rectifying Potassium Channel, Belinda Akpa, Nicolas Barbera, Irena Levitan

Biology and Medicine Through Mathematics Conference

No abstract provided.


Modeling Pharmaceutical Inhibition Of Glucose-Stimulated Renin-Angiotensin System In Kidneys, Ashlee N. Ford Versypt, Minu R. Pilvankar, Hui Ling Yong May 2018

Modeling Pharmaceutical Inhibition Of Glucose-Stimulated Renin-Angiotensin System In Kidneys, Ashlee N. Ford Versypt, Minu R. Pilvankar, Hui Ling Yong

Biology and Medicine Through Mathematics Conference

No abstract provided.


Cortical Statistical Correlation Tomography Of Eeg Resting State Networks, Chuang Li, Han Yuan, Guofa Shou, Yoon-Hee Cha, Sridhar Sunderam, Walter Besio, Lei Ding May 2018

Cortical Statistical Correlation Tomography Of Eeg Resting State Networks, Chuang Li, Han Yuan, Guofa Shou, Yoon-Hee Cha, Sridhar Sunderam, Walter Besio, Lei Ding

Biomedical Engineering Faculty Publications

Resting state networks (RSNs) have been found in human brains during awake resting states. RSNs are composed of spatially distributed regions in which spontaneous activity fluctuations are temporally and dynamically correlated. A new computational framework for reconstructing RSNs with human EEG data has been developed in the present study. The proposed framework utilizes independent component analysis (ICA) on short-time Fourier transformed inverse source maps imaged from EEG data and statistical correlation analysis to generate cortical tomography of electrophysiological RSNs. The proposed framework was evaluated on three sets of resting-state EEG data obtained in the comparison of two conditions: (1) healthy …


Application Of Composite Hydrogels To Control Physical Properties In Tissue Engineering And Regenerative Medicine, Cassidy Sheffield, Kaylee Meyers, Emil Johnson, Rupak Rajachar May 2018

Application Of Composite Hydrogels To Control Physical Properties In Tissue Engineering And Regenerative Medicine, Cassidy Sheffield, Kaylee Meyers, Emil Johnson, Rupak Rajachar

Michigan Tech Publications, Part 1

The development of biomaterials for the restoration of the normal tissue structure–function relationship in pathological conditions as well as acute and chronic injury is an area of intense investigation. More recently, the use of tailored or composite hydrogels for tissue engineering and regenerative medicine has sought to bridge the gap between natural tissues and applied biomaterials more clearly. By applying traditional concepts in engineering composites, these hydrogels represent hierarchical structured materials that translate more closely the key guiding principles required for improved recovery of tissue architecture and functional behavior, including physical, mass transport, and biological properties. For tissue-engineering scaffolds in …


Numerical Assessment Of The Convective Heat Transfer In Rotating Detonation Combustors Using A Reduced-Order Model, James Braun, Jorge Sousa, Guillermo Paniagua May 2018

Numerical Assessment Of The Convective Heat Transfer In Rotating Detonation Combustors Using A Reduced-Order Model, James Braun, Jorge Sousa, Guillermo Paniagua

School of Aeronautics and Astronautics Faculty Publications

The pressure gain across a rotating detonation combustor offers an efficiency rise and potential architecture simplification of compact gas turbine engines. However, the combustor walls of the rotating detonation combustor are periodically swept by both detonation and oblique shock waves at several kilohertz, disrupting the boundary layer, resulting in a rather complex convective heat transfer between the fluid and the solid walls. A computationally fast procedure is presented to calculate this extraordinary convective heat flux along the detonation combustor. First, a numerical model combining a two-dimensional method of characteristics approach with a monodimensional reaction model is used to compute the …


Reimagining Icarus: Ethics, Law And Policy Considerations For Commercial Human Spaceflight, Sara M. Langston May 2018

Reimagining Icarus: Ethics, Law And Policy Considerations For Commercial Human Spaceflight, Sara M. Langston

Publications

Commercial human spaceflight presents an area for engaging novel human activity and objectives, to include space exploration, entertainment, transportation and extraterrestrial resource acquisition. The inherent dangers and lack of scientific and medical certainty involved however raise interrelated questions of ethics, bioethics, law and public policy. This is particularly the case with spaceflight participant (SFP) screening, selection, and commercial human spaceflight activities where regulations are currently silent or lacking. In the absence of established law, ethics can play an important role by informing industry standards, policies and best practices. Understanding the fundamental ethical values at stake in the application of new …


Experimental Evaluation Of Lignocellulosic Biomass Pyrolysis By Dielectric Heating And Thermocatalytic Upgrading Of Pyrolysis Vapors Via Iron-Doped Montmorillonite Clay Catalyst, Candice Raffaela Ellison May 2018

Experimental Evaluation Of Lignocellulosic Biomass Pyrolysis By Dielectric Heating And Thermocatalytic Upgrading Of Pyrolysis Vapors Via Iron-Doped Montmorillonite Clay Catalyst, Candice Raffaela Ellison

LSU Doctoral Dissertations

This work is an investigation of microwave-assisted biomass pyrolysis and thermocatalytic upgrading of pyrolysis vapors. In the first two chapters, the microwave susceptibility of mixtures of biomass with potential microwave absorbers are characterized by dielectric measurements at microwave frequencies. Dielectric constant and dielectric loss factor of biomass mixtures with char and biomass mixtures with bentonite are found to increase quadratically with increasing weight percent of char or bentonite.

Chapter 3 presents a finite element model, developed in COMSOL Multiphysics, comparing two waveguide applicator configurations for microwave processing using biomass as a model material. A standing wave configuration results in intense …


Contents, Adfsl May 2018

Contents, Adfsl

Annual ADFSL Conference on Digital Forensics, Security and Law

No abstract provided.


Front Matter, Adfsl May 2018

Front Matter, Adfsl

Annual ADFSL Conference on Digital Forensics, Security and Law

No abstract provided.


Development Of Digital Diary For Enhanced Parental School Involvement In Tanzania, Sekione R. Jeremiah, Joel S. Mtebe Phd May 2018

Development Of Digital Diary For Enhanced Parental School Involvement In Tanzania, Sekione R. Jeremiah, Joel S. Mtebe Phd

The African Journal of Information Systems

The study examined the use of digital diary as a tool for enhancing parental school involvement in Tanzania. The development of the digital diary followed eXtreme Programming agile method where 87 parents and 6 teachers from St. Florence school were involved. Parents and teachers were given six months to use the tool before testing for its effectiveness using data from 7 teachers and 156 parents through semi-structured interviews and questionnaires respectively. The study found that the majority of respondents (84.4% of parents and 96.7% of teachers) indicated that the digital diary was useful tool as enabled them to track children’s …


Login Authentication With Facial Gesture Recognition, Ruiwen Li, Songjie Cai, Tor Saxberg May 2018

Login Authentication With Facial Gesture Recognition, Ruiwen Li, Songjie Cai, Tor Saxberg

Computer Science and Engineering Senior Theses

Facial recognition has proven to be very useful and versatile, from Facebook photo tagging and Snapchat filters to modeling fluid dynamics and designing for augmented reality. However, facial recognition has only been used for user login services in conjunction with expensive and restrictive hardware technologies, such as in smart phone devices like the iPhone x. This project aims to apply machine learning techniques to reliably distinguish user accounts with only common cameras to make facial recognition logins more accessible to website and software developers. To show the feasibility of this idea, we created a web API that recognizes a users …


Risk Assessment Of Concrete Gravity Dams Under Earthquake Loads, Ufuk Sen May 2018

Risk Assessment Of Concrete Gravity Dams Under Earthquake Loads, Ufuk Sen

LSU Master's Theses

Dams are important structures to supply water for irrigation or drinking, to control flood, and to generate electricity. In seismic regions, the structural safety of concrete gravity dams is important due to the high potential of life and economic loss if they fail. Therefore, the seismic analysis of existing dams in seismically active regions is very crucial to predict responses of dams to ground motions. In this thesis, earthquake response of concrete gravity dams is investigated using the finite element (FE) method. The selected dam is the Pine Flat Dam which is located in the Central Valley of Fresno County, …


Effect Of Recycled Geopolymer Concrete Aggregate On Strength Development And Consistence Of Portland Cement Concretes, Napoleana-Anna Chaliasou, Andrew Heath, Juliana Calabria Holley, Kevin Paine May 2018

Effect Of Recycled Geopolymer Concrete Aggregate On Strength Development And Consistence Of Portland Cement Concretes, Napoleana-Anna Chaliasou, Andrew Heath, Juliana Calabria Holley, Kevin Paine

Alkali Activated Materials and Geopolymers: Versatile Materials Offering High Performance and Low Emissions

Numerous studies have shown that production of geopolymer cement concretes can have lower carbon emissions compared to Portland cement concretes. However, for a full lifecycle assessment of environmental impacts, scenarios for the end of structures’ design life of must be considered, including reuse options. The work presented here is part of a wider study investigating the recyclability of fly ash-slag geopolymer cement (GC) concrete as an aggregate in Portland cement (PC) concretes.

Three types of GC concretes with varying Na2O % per mass of precursor and SiO2/Na2O molar ratio were produced in the laboratory. …


Acid Geopolymer Materials Based On Different Aluminosilicate Sources, Sylvie Rossignol, Jenny Jouin, Virginie Mathivet, Michel Parlier May 2018

Acid Geopolymer Materials Based On Different Aluminosilicate Sources, Sylvie Rossignol, Jenny Jouin, Virginie Mathivet, Michel Parlier

Alkali Activated Materials and Geopolymers: Versatile Materials Offering High Performance and Low Emissions

Geopolymers synthetized from the reaction of metakaolin (or alumino-silicate) in an alkali medium are studied since decades [1]. However, in order to develop composites, alkali medium is undesirable due to the detrimental effect of alkali ions on fibers. As an alternative, the use of an acid medium seems promising as some authors demonstrated an increase of mechanical properties with acid-based geopolymers [2, 3]. The aim of this work is to investigate the various formulations and to understand the reactional mechanisms.

The work is based on the activation of an alumino-silicate source with phosphoric acid to obtain geopolymer The various formulations …


Us Airline Stock Market Performance And Change In Investor Behavior Over The Great Recession Of 2008, Rebecca Wood, Jayendra Gokhale May 2018

Us Airline Stock Market Performance And Change In Investor Behavior Over The Great Recession Of 2008, Rebecca Wood, Jayendra Gokhale

Publications

We study the relationship of West Texas Intermediate (WTI) crude oil returns and the stock market returns with the US airline stocks before, during and after the 2008 financial crisis. We confirm the positive relationship of the airline stock returns with the overall market and the negative relationship with WTI. However, we find that the crisis led to a structural change in this relationship. Our results differ for low-cost airlines which absorb the oil price shock better as compared to legacy airlines. We also find that there is a difference in the relationship between the airline stock returns and WTI …


Study On Components Determination And Performance Evaluation Of Ls Pre-Maintenance Agent, Yuxiang Tian, Biao Ma, Ke Tian, Ning Li, Xueyan Zhou May 2018

Study On Components Determination And Performance Evaluation Of Ls Pre-Maintenance Agent, Yuxiang Tian, Biao Ma, Ke Tian, Ning Li, Xueyan Zhou

Michigan Tech Publications, Part 1

Adequate maintenance and taking active preventive measures can effectively prevent the early disease of asphalt pavements before significant damage occurs. By developing a light screening preventive maintenance agent (LS pre-maintenance agent) for strong ultraviolet (UV) radiation areas, based on the asphalt aging and regeneration mechanism, we analyzed the function and basic components and determined the optimum components ratio based on the best proportion of penetrant and solvent oil for solubility. The optimum ratio for quick-drying and long-term storage ability is the mass ratio of rock asphalt, reducing agent, penetrant, and solvent oil, which is 30:20:20:30. The light-shield agent is 5% …


Investigation Of Thermal History In Large Area Projection Sintering, An Additive Manufacturing Technology, Justin Nussbaum May 2018

Investigation Of Thermal History In Large Area Projection Sintering, An Additive Manufacturing Technology, Justin Nussbaum

USF Tampa Graduate Theses and Dissertations

The goal of this work is to explore the benefits of using long exposure times with polymer powder bed fusion additive manufacturing processes and examine the feasibly of this new application as a manufacturing process. It is well known that the sintering which occurs in these systems are a time and temperature dependent process. However, the most common powder bed fusion systems use a laser which scans and heats the powdered feedstock for microseconds at a time, leaving insufficient time for the polymer to fully melt and/or fuse, leading to reduced mechanical properties. Little has been published on the effects …


Thermally Stable Super-Hydrophobic Surface Creation, Caleb Turner May 2018

Thermally Stable Super-Hydrophobic Surface Creation, Caleb Turner

Maseeh Summer Undergraduate Research Experience

Thermally stable super-hydrophobic surface coatings are critical to applications in low gravity fluid dynamics, and in particular Leidenfrost effects. The challenges of manufacturing different super-hydrophobic coatings that are thermally stable, semi-transparent, and environmentally safe at desired operating temperatures is pursued in order to explore the applications of such coatings aboard spacecraft. A catalog of surface coating manufacturing procedures is tabulated with measures for static contact angle, thermal stability, and transparency. These quantities and methods serve as a foundation for both technology applications and follow on experimentation concerning low gravity fluid mechanics at the Portland State Dryden Drop Tower lab.


Promoting Global Clinical Care And Research For Children With Orthopaedic Disabilities Through Motion Analysis Technology, Jacob R. Rammer, Joycie Eulah Abiera, Monica Arroyo, Luis Fernando Caicedo, Karl Canseco, Christopher Constantino, Filipe Haces Garcia, Jorge Gomez, Nikhil T. Kurapati, Mariano Gonzalez Lugo, Terence Miller, Wilfredo Agredo Rodriguez, Carlo Emmanuel Sumpaico, Gerald F. Harris May 2018

Promoting Global Clinical Care And Research For Children With Orthopaedic Disabilities Through Motion Analysis Technology, Jacob R. Rammer, Joycie Eulah Abiera, Monica Arroyo, Luis Fernando Caicedo, Karl Canseco, Christopher Constantino, Filipe Haces Garcia, Jorge Gomez, Nikhil T. Kurapati, Mariano Gonzalez Lugo, Terence Miller, Wilfredo Agredo Rodriguez, Carlo Emmanuel Sumpaico, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Human motion analysis is a tool used to understand orthopaedic disabilities in children and to plan and monitor treatment strategies. It enables clinicians to quantitatively describe rehabilitative progress, plan surgeries, and conduct research. While this technology is prevalent in major academic medical centers, access is lacking in many regions throughout the world. This paper presents a novel approach to offer more accessible technology at greatly reduced cost. Current applications are underway in the Philippines, Mexico, and Colombia. Through international partnerships, improvements in clinical care, medical education, and research have been observed.


Selective Flocculation Separation Of Fine Hematite From Quartz Using A Novel Grafted Copolymer Flocculant, Jinxia Zhang, Weiguang Sun, Zhiyong Gao, Fusheng Niu, Long Wang, Yawei Zhao, Yuesheng Gao May 2018

Selective Flocculation Separation Of Fine Hematite From Quartz Using A Novel Grafted Copolymer Flocculant, Jinxia Zhang, Weiguang Sun, Zhiyong Gao, Fusheng Niu, Long Wang, Yawei Zhao, Yuesheng Gao

Michigan Tech Publications, Part 1

Beneficiation of ultrafine mineral particles (typically with an average size less than 20 µm) remains a critical problem for the mineral processing industry. Selective flocculation technique has been found to show great potential to tackle this problem, whose success mainly depends on the selective adsorption of a flocculant on the target mineral particles. In this work, a novel copolymer flocculant was synthesized by grafting starch and acrylamide, which for the first time, was employed in the flocculation separation of fine hematite from quartz. The composites of the grafted copolymer flocculant (GCF) were characterized by Fourier transform infrared spectroscopy (FTIR) and …


Ltpp Data Analysis: Factors Affecting Pavement Roughness For The State Of California, Pedro Zavanga, Alisha Khanal, Mena I. Souliman May 2018

Ltpp Data Analysis: Factors Affecting Pavement Roughness For The State Of California, Pedro Zavanga, Alisha Khanal, Mena I. Souliman

Civil Engineering Faculty Publications and Presentations

The contributions of pavement structure and features, rehabilitation techniques, climatic conditions, traffic levels, layer materials and properties, pavement distress, and other factors causing changes in pavement smoothness are not well documented. As a result, it becomes difficult to select the appropriate pavement structure, design features and rehabilitation strategies to ensure pavement smoothness. This study focuses on analysing the available LTPP data for asphalt pavements in California by investigating the correlation between the pavement roughness and the effect of pavement temperature, precipitation, fatigue, age of pavement, rutting, and the average annual daily truck traffic. IRI has been identified as the factor …


Real Soils Versus Fake Soils: Does Something Other Than Clay Minerals Influence Geopolymerisation Behavior In Real Soils?, Alastair Marsh, Pascaline Patureau, Mark Evernden, Pete Walker, Andrew Heath May 2018

Real Soils Versus Fake Soils: Does Something Other Than Clay Minerals Influence Geopolymerisation Behavior In Real Soils?, Alastair Marsh, Pascaline Patureau, Mark Evernden, Pete Walker, Andrew Heath

Alkali Activated Materials and Geopolymers: Versatile Materials Offering High Performance and Low Emissions

Uncalcined geopolymer-stabilised soils have shown potential for replacing concrete and fired clay as low carbon masonry materials. There is now a good fundamental understanding of how aluminosilicate precursors react to form geopolymer phases in simple systems, but there is a knowledge gap for the more complex systems of real soils where minor phases may influence behaviour. Because the clay minerals and their proportions differ between soils, as well as minor phases present, we are still not able to easily predict which soils are suitable for geopolymer stabilisation. In this study, a comparison was made for the alkali activation of real …


Investigation Of The Relationship Between The Condensed Structure And The Chemically Bonded Water Content In The Network Of Geopolymer Cements, Herve Tchakoute Kouamo, Sorelle J. K. Melele, Claus H. Rüscher, Elie Kamseu, Cristina Leonelli May 2018

Investigation Of The Relationship Between The Condensed Structure And The Chemically Bonded Water Content In The Network Of Geopolymer Cements, Herve Tchakoute Kouamo, Sorelle J. K. Melele, Claus H. Rüscher, Elie Kamseu, Cristina Leonelli

Alkali Activated Materials and Geopolymers: Versatile Materials Offering High Performance and Low Emissions

The main objective of this work was to investigate the relationship between the condensed structure and the chemically bonded water content in the metakaolin-based geopolymer network. The kaolinite clay used in this work as an aluminosilicate source was transformed to metakaolin by calcination at 700 °C. The powder of the waste glass and the silica fume were used as silica sources for the synthesis of the hardeners. The obtained hardeners were characterized by infrared spectroscopy and MAS-NMR 29Si. The metakaolin and the hardeners were used for producing geopolymers cements. The synthesized products were characterized by X-ray diffractometry, infrared spectroscopy, …


Fracture Initiation In A Transversely Isotropic Solid: Transient Three Dimensional Analysis, Louis Milton Brock May 2018

Fracture Initiation In A Transversely Isotropic Solid: Transient Three Dimensional Analysis, Louis Milton Brock

Mechanical Engineering Faculty Publications

A transversely isotropic solid is at rest, and contains a semi-infinite, plane crack. The axis of rotational material symmetry lies in the crack plane. Application of normal point forces to each face of the crack causes transient 3D growth. The related problem of discontinuities in displacement and traction that exist on regions that exhibit dynamic similarity is first considered. Analytic results are obtained in integral transform space. These lead to equations of the Wiener–Hopf type for the fracture problem. Analytic solutions are again obtained and, upon inversion, subjected to a dynamic energy release rate criterion that includes kinetic energy. A …