Engineering Commons^™

An Approach To Model Plastic Deformation Of Metallic Plates In Hypervelocity Impact Experiments, Shawoon Kumar Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Space structures are subjected to micro-meteorite impact at extremely high velocities of several kilometers per second. Similarly, design of military equipment requires understanding of material behavior under extremely high pressure and temperature. Study of material behavior under hypervelocity impact (HVI) poses many challenges since few researchers so far have approached this problem. Material models, equations of the state, and fracture mechanics are not well understood under these conditions.

The objective of this research is to present an approach for studying plastic deformation of metallic plates under HVI conditions. A two-stage light gas gun can be used to simulate these conditions …

Crystalline Phase Change In Steel Alloys Due To High Speed Impact, Muna Slewa

UNLV Theses, Dissertations, Professional Papers, and Capstones

The effect of hypervelocity projectile impact on the crystalline grain structure near the target impact location of A36 steel has been studied. A36 steel is a mostly single phase body centered cubic material (BCC). Impact velocities ranged from 3.54 to 6.70 km/sec. Target materials were studied before and after impact to determine if these impact conditions result in a phase change of the A36. Scanning electron microscopy, electron back-scatter diffraction, and x-ray diffraction methods were used to investigate deformation, lattice defects, twinning, and phase transformation. A limited number of impacted targets made from 304L and HY100 steels were also examined. …

Impact Of 1-Hydroxybenzotriazole Dosing On Trace Organic Contaminant Degradation By Laccase, Ngoc Luong Nguyen, Faisal Ibney Hai, Jinguo Kang, S Faraj Magram, William Price, Long Nghiem

Faisal I Hai

This study investigated the removal of five selected non-phenolic trace organic contaminants (TrOC) by extracellular enzyme extract from a white-rot fungus. Except diclofenac, no other investigated non-phenolic TrOC were degraded by the extracellular enzyme extract. Improvement of enzymatic degradation of all TrOC was achieved in the presence of a redox mediator, namely, 1-hydroxybenzotriazole (HBT). However, the enhancement of degradation was mediator concentration-specific. A significant improvement in degradation at higher dosage than 0.1 mM (HBT) was achieved.

Implementation Of Remote Sensing Technology On The I-64 Bridge Over Us60, Issam Harik, Ching Choo, Abheetha Peiris, Dan Eaton

Issam E. Harik

Remote sensing devices have been implemented on the I-64 Bridges over US60 in Franklin County, KY. One of the girders in the westbound bridge has been previously repaired due to unexpected fatigue cracking. The exterior girder in the eastbound bridge has shown signs of impacts due to the traversing trucks on US60. Sensing and recording devices such as strain and temperature gauges, infrared sensors, ultrasonic height detectors, and an accelerometer have been installed. Specifically, eleven strain gauges are used on the repaired girder, impacted girders, and girders adjacent to them. Two sets of infrared sensors, ultrasonic detectors, and video cameras …

Multi-Barge Flotilla Impact Forces On Bridges, Peng Yuan, Issam Harik, Michael Davidson

Issam E. Harik

The current AASHTO equations for barge impact loads are based on scale models of barges, and may not accurately predict impact loads on bridge piers. The results of this study produce more realistic flotilla impact design loads, potentially leading to a reduction in construction costs of bridges over navigable waterways. The objectives of this study are: (1) To conduct theoretical finite element analysis on various types of flotillas impacting bridge piers. The flotillas and the respective barges will be of the type commonly traversing Kentucky’s waterways; and (2) To generate design equations for barge/flotilla impact loads. The study concludes the …

Progressive Damage In Stitched Composites Under Impact Loading, Kwek Tze Tan, N. Watanabe, A. Yoshimura, Y. Iwahori, T. Ishikawa

Dr. Kwek-Tze Tan

Damage in carbon fibre reinforced plastics (CFRP) due to impact loading is an extremely complex phenomenon that comprises of multiple failure mechanisms like intra-laminar matrix cracks, interlaminar delamination, fibre pull-out and fibre fracture. In stitched composites, impact damage behavior is further complicated by the presence of through-thickness stitching [1, 2], which not only favorably increases mode I/II interlaminar strength [3, 4], but also inevitably creates geometrical defects like weak resin-rich pockets around stitch threads and misalignment of in-plane fibres. Computational modeling has been used to simulate progressive damage effectively [5]. However, the complexity of impact damage progression in stitched composites …

The Design, Build, And Validation Of A Hybrid Tower Used To Conduct Helmet Impact Tests, Darren Benn

UNLV Theses, Dissertations, Professional Papers, and Capstones

The National Operating Committee on Standards for Athletic Equipment (NOCSAE) was established to enlist research directed towards the reduction of head injuries in organized sports. The function of the test methods developed by NOCSAE is to provide the blueprint for reliable and repeatable procedures to measure the evaluation of various types of protective sports headgear and projectiles. In addition, the methods also govern hardware such as testing apparatus and data acquisition instrumentation. In helmet testing, the method dictates whether the impact is induced by a projectile system or by a drop tower system with an anvil at the base. Altogether, …

Design And Construction Of A Full-Scale Lateral Impact Testing Facility, Cody Aaron Mitchell

Masters Theses

The goal of this work is to design and construct a full scale lateral impact testing facility that is capable of recreating the damage that would be created by an overheight vehicle collision. This was accomplished by impacting a test specimen with an 8000 lbs. impact cart. The impact cart is raised on an elevated track and allowed to roll down the track with a change in height of 10 ft. This change in height is what provides the impact force necessary to recreate an overheight vehicle collision. The track is constructed out of wood and is designed to withstand …

Assessment Of The Impact Of Clothing And Environmental Conditions On Visible Light 3d Scanning, Pann Ajjimaporn, Jeremy Straub, Scott Kerlin

Jeremy Straub

The quality of models produced by visible light 3D scanners is influenced by multiple factors. To max-imize model accuracy and detail levels, the correct combination of lighting texture, subject posture and software usage must be selected. The work described herein has been performed to measure the effect of different lighting and envi-ronmental conditions on human 3D scanning results.

Impact Perforation Of Sandwich Panels With Coremat®, Michelle Hoo Fatt, Dushyanth Sirivolu

Dr. Michelle S. Hoo Fatt

Analytical solutions for the quasi-static and low-velocity perforation of sandwich panels with woven roving E-glass/vinyl ester facesheets and Coremat were derived. A multi-stage perforation process involving delamination, debonding, core shear fracture and facesheet fracture was used to predict the quasi-static failure load and ballistic resistance of the panel. The high core-crushing resistance and damping of the Coremat resulted in rupture of the distal facesheet before the incident facesheet during panel perforation because they limited the amount of local indentation compared with global panel deformation. Analytical predictions of the quasi-static load-deflection response and the dynamic contact force history were within 10% …

Effect Of N-Butanol And Diethyl Ether As Oxygenated Additives On Combustion-Emission-Performance Characteristics Of A Multiple Cylinder Diesel Engine Fuelled With Diesel-Jatropha Biodiesel Blend

Faculty of Engineering University of Malaya

Jatropha biodiesel is considered as one of the most prospective renewable energy sources of Malaysia in recent years. Hence, an investigation was conducted for the improvement of jatropha biodiesel-diesel blend with the addition of 5-10% n-butanol and diethyl ether by vol. which are commonly known as oxygenated cold starting additive. Engine tests were conducted at variable speed, ranging from 1000 rpm to 3000 rpm at constant 80 N m torque on a 4-cylinder turbocharged indirect injection diesel engine. Engine performance parameters like brake specific fuel consumption, brake specific energy consumption, brake thermal efficiency and engine emissions like carbon monoxide, unburned …

Is There A Relationship Between Research Sponsorship And Publication Impact? An Analysis Of Funding Acknowledgments In Nanotechnology Papers, Jue Wang, Philip Shapira

Philip Shapira

This study analyzes funding acknowledgments in scientific papers to investigate relationships between research sponsorship and publication impacts. We identify acknowledgments to research sponsors for nanotechnology papers published in the Web of Science during a one-year sample period. We examine the citations accrued by these papers and the journal impact factors of their publication titles. The results show that publications from grant sponsored research exhibit higher impacts in terms of both journal ranking and citation counts than research that is not grant sponsored. We discuss the method and models used, and the insights provided by this approach as well as it …

Biodiesel Production, Characterization, Diesel Engine Performance, And Emission Characteristics Of Methyl Esters From Aphanamixis Polystachya Oil Of Bangladesh

Faculty of Engineering University of Malaya

This paper presents the prospect of biodiesel derived from Aphanamixis polystachya oil in diesel engine. The study deals with the physicochemical properties of A. polystachya methyl ester (APME) and its blends followed by evaluation of performance and emission characteristics of APME5 and APME10 in a multi-cylinder diesel engine. It has been observed that the properties of biodiesel and its blends are compatible with the ASTM D6751 and ASTM D7467 standards, respectively. It was found that, APME5 and APME10 showed an average 0.9% and 1.81% reduction in torque and 0.9% and 2.1% reduction in brake power (BP), and 0.87% and 1.78% …

Design And Biomechanical Performance Analysis Of A User-Friendly Orthotic Device

Faculty of Engineering University of Malaya

Material selection and proper design are essential for developing a new product, especially biomedical devices. Stance-control-orthosis (SCO) are walking assistive device for the patients with weak quadriceps. This manuscript presents the development of a prefabricated SCO with suitable material and design. It is 45% lighter than commercially available prefabricated device. It contains some adjustable features to make it competent for wide range of patients in terms of height (153-183 cm) and weight. Finite element analysis (FEA) was used for selecting the best material and optimizing weight of different components of this device. Basic structures the device were made of aluminum …

Evaluation Of N-Butanol As An Oxygenated Additive To Improve Combustion-Emission-Performance Characteristics Of A Diesel Engine Fuelled With A Diesel-Calophyllum Inophyllum Biodiesel Blend

Faculty of Engineering University of Malaya

Alexandrian laurel or Calophyllum inophyllum oil is considered as one of the most forthcoming non-edible biodiesel sources in recent years. In the present study, the relative improvement of an Alexandrian laurel biodiesel-diesel blend (AL20) was attempted with the addition of 5-10% n-butanol (by vol), which is often used as an oxygenated cold starting additive. Constant 80 Nm torque at variable engine speed, ranging from 1000 to 3000 rpm was chosen as the operating condition on a 4-cylinder turbocharged, water cooled diesel engine. Brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC) and brake thermal efficiency (BTE) was measured to …

Análisis De Impacto Expost De La Implementación De Medidores Prepago Para La Empresa De Energía De Boyacá Ebsa S.A E.S.P, Zaret Natalia Mayorga Roncancio, Andrea Yesenia Molano Gómez

Ingeniería Eléctrica

Este trabajo presenta el análisis de impacto de la implementación de medidores prepago de servicio eléctrico en zonas rurales, a partir de los antecedentes técnicos y regulatorios en el país, se determinaron los tipos de medidores empleados en la actualidad en las zonas rurales colombianas, identificando características operacionales de este sistema, políticas regulatorias que se necesitaron para implementar este sistema, condiciones socioculturales, ambientales y económicas, para así identificar y analizar los impactos en los distintos aspectos sostenibles asociados con estas experiencias. Por último, este estudio identifica las ventajas y desventajas reales de la aplicación de estos sistemas para las empresas …

Behavior Of Reinforced Concrete Panels Subject To Impact By Non-Deformable Projectiles, Amer Abdel Karim Alkloub

Open Access Dissertations

In impact resistance of reinforced concrete (RC) panels against projectiles the contribution of the orthogonal mesh reinforcement has been ignored. In this study the contribution of mesh reinforcement to impact resistance and itseffect on the nature of local damage caused by impact of non-deformable projectiles are investigated. The investigation included a combination of 53 experiments and series of finite-element based numerical simulations. Three levels of local damage modes were investegated based on the severity of the degree of damage in the impacted panels. Mesh reinforcement ratio within the range of reinforcement ratio considered, namely 0.19% to 0.48%, was irrelevant to …

Summary Of The Impact Of The Inclusion Of Mobile Phone Numbers Into The Nsw Population Health Survey In 2012, Margo Barr, Raymond A. Ferguson, Jason J. Van Ritten, Phillip J. Hughes, David G. Steel

Faculty of Engineering and Information Sciences - Papers: Part A

Although it was estimated that 20% of the population in Australia were mobile-only phone users in 2010, the inclusion of mobile numbers into computer-assisted telephone interviews (CATI) behavioural risk factor surveys did not occur until 2012. Methods: Three papers have been published describing the methods, weighting strategy and the impact in detail of including mobile numbers into the NSW Population Health Survey (NSWPHS). This paper identifies the important components of those papers and summarises them for a broader audience. Results: In the 2012 NSWPHS, 15,214 (15,149 with weights) interviews were completed (64% landline frame; 36% mobile frame). Response, cooperation and …