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Modeling And Computation Of The Maximum Braking Energy Speed For Transport Category Airplanes, Nihad E. Daidzic 2019 AAR Aerospace Consulting, LLC

Modeling And Computation Of The Maximum Braking Energy Speed For Transport Category Airplanes, Nihad E. Daidzic

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

Transport-category or FAR/CS 25 certified airplanes may occasionally become braking energy capacity limited. Such limitation may exist when heavy airplanes are departing airports at high-density altitudes, on relatively long runways, and/or possibly with some tailwind component. A maximum braking energy VMBE speed exists which may limit the maximum allowable takeoff decision/action speed V1. The ever-existing possibility of high-speed rejected takeoff in such conditions may also limit the airplane gross weight for declared available distances. To gain deeper insights and acquire better understanding of the topic, a theoretical model of the maximum braking energy and the related VMBE ...


Mechanical And Tribological Behaviour Of Treated And Untreated Moringa Oleifera Pods Fiber Reinforced Epoxy Polymer Composite For Packaging Applications, prakash sampath, Senthil Kumar V.S Dr 2019 Anna University

Mechanical And Tribological Behaviour Of Treated And Untreated Moringa Oleifera Pods Fiber Reinforced Epoxy Polymer Composite For Packaging Applications, Prakash Sampath, Senthil Kumar V.S Dr

Journal of Applied Packaging Research

Researchers now focus on the use of natural fiber polymer composites materials for packing applications. This attention is due to their low cost and renewable characteristics. Fabrication of composites with the use of renewable resources has many benefits of alternating from an appropriate management and reduction in industrial wastages, ecofriendly behaviour to cost effectiveness. The artificial fibers in packing industries can be replaced by natural fibers in the areas where stiffness and high strength are not the primary requirement. In the last decade the use of Natural fibers in the place of artificial fibers for reinforcements in epoxy resin matrix ...


Final Design Review: Wear Test Machine, Justin Ju-Han Hou, Abraham Jack Mitchell, Alexandra Denae Pavano, Jahyun Kaylla Son 2019 California Polytechnic State University, San Luis Obispo

Final Design Review: Wear Test Machine, Justin Ju-Han Hou, Abraham Jack Mitchell, Alexandra Denae Pavano, Jahyun Kaylla Son

Mechanical Engineering

A California Polytechnic State University Senior Project team has been tasked by Marvin Engineering Co. to design and build a friction wear test fixture; the fixture is to characterize the coefficient of friction and potential friction wear of various industry adopted metal pairings in an oxygen-free environment. This final design review serves to document project research, full design process, method of operation of final product, and a comprehensive testing procedure.

The R&D department at Marvin Engineering Co. proposed this investigation in order to explore the phenomenon of friction and adhesive wear, specifically the occurrence of galling between stainless steel ...


Characterization Of A Novel Variable Friction Connection For Semi-Active Cladding System, Yongqiang Gong, Liang Cao, Simon Laflamme, Spencer Quiel, James Ricles, Douglas Taylor 2018 Iowa State University

Characterization Of A Novel Variable Friction Connection For Semi-Active Cladding System, Yongqiang Gong, Liang Cao, Simon Laflamme, Spencer Quiel, James Ricles, Douglas Taylor

Civil, Construction and Environmental Engineering Publications

Cladding systems are conventionally designed to serve architectural purposes and protect occupants from the environment. Some research has been conducted in altering the cladding system in order to provide additional protection against natural and man‐made hazards. The vast majority of these solutions are passive energy dissipators, applicable to the mitigation of single types of hazards. In this paper, we propose a novel semiactive variable friction device that could act as a connector linking a cladding panel to the structural system. Because of its semiactive capabilities, the device, here termed variable friction cladding connection (VFCC), could be utilized to mitigate ...


Understanding The Evolution Of Surface Texture Under Boundary Lubrication, Salil T. Bapat 2018 University of Arkansas, Fayetteville

Understanding The Evolution Of Surface Texture Under Boundary Lubrication, Salil T. Bapat

Theses and Dissertations

The objective of this research was to understand the evolution of surface texture under boundary/mixed lubrication (BL). Significant material/energy losses occur during BL because of direct contact between the two surfaces. Traditionally, tribofilms have been studied extensively for BL while textures have been used as a static engineering design parameter to enhance lubricant film properties. However, texture is dynamic at the tribological mating interface, where both physical and chemical interactions are continuously modulated. The evolution and the interplay between the tribofilm and texture is least studied in the literature, which is the focus of this research.

MoS2-based lubricants ...


Modeling Residual Stress Development In Hybrid Processing By Additive Manufacturing And Laser Shock Peening, Guru Charan Reddy Madireddy 2018 University of Nebraska - Lincoln

Modeling Residual Stress Development In Hybrid Processing By Additive Manufacturing And Laser Shock Peening, Guru Charan Reddy Madireddy

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

The term “hybrid” has been widely applied to many areas of manufacturing. Naturally, that term has found a home in additive manufacturing as well. Hybrid additive manufacturing or hybrid-AM has been used to describe multi-material printing, combined machines (e.g., deposition printing and milling machine center), and combined processes (e.g., printing and interlayer laser re-melting). The capabilities afforded by hybrid-AM are rewriting the design rules for materials and adding a new dimension in the design for additive manufacturing paradigm. This work focuses on hybrid-AM processes, which are defined as the use of additive manufacturing (AM) with one or more ...


Evaluation Of High Velocity Wear, Armando DeLeon 2018 Air Force Institute of Technology

Evaluation Of High Velocity Wear, Armando Deleon

Theses and Dissertations

The HHSTT located at Holloman Air Force Base conducts hypersonic testing in a unique way. Rather than perform cost prohibitive flight testing or hypersonic wind tunnel testing, a rocket-powered sled propels test articles down a track. This test setup has been used to test at speeds up to 2885 m/s (~Mach 8.6). The sled is kept on the rails by utilizing slippers, fabricated to wrap around the rail [1]. This slipper design keeps the sled from separating from the rail during a test due to the airflow producing lift, in a designed effort to minimize the wear that ...


Powder Bed Surface Quality And Particle Size Distribution For Metal Additive Manufacturing And Comparison With Discrete Element Model, Irene Yee 2018 California Polytechnic State University, San Luis Obispo

Powder Bed Surface Quality And Particle Size Distribution For Metal Additive Manufacturing And Comparison With Discrete Element Model, Irene Yee

Master's Theses and Project Reports

Metal additive manufacturing (AM) can produce complex parts that were once considered impossible or too costly to fabricate using conventional machining techniques, making AM machines an exceptional tool for rapid prototyping, one-off parts, and labor-intensive geometries. Due to the growing popularity of this technology, especially in the defense and medical industries, more researchers are looking into the physics and mechanics behind the AM process. Many factors and parameters contribute to the overall quality of a part, one of them being the powder bed itself. So far, little investigation has been dedicated to the behavior of the powder in the powder ...


Mechanical Wear Debris Feature, Detection, And Diagnosis: A Review, Wei Hong, Wenjian Cai, Shaoping Wang, Mileta M. Tomovic 2018 Old Dominion University

Mechanical Wear Debris Feature, Detection, And Diagnosis: A Review, Wei Hong, Wenjian Cai, Shaoping Wang, Mileta M. Tomovic

Engineering Technology Faculty Publications

Mechanical debris is an important product of friction wear, which is also a crucial approach to know the running status of a machine. Many studies have been conducted on mechanical debris in related fields such as tribology, instrument, and diagnosis. This paper presents a comprehensive review of these studies, which summarizes wear mechanisms (e.g., abrasive wear, fatigue wear, and adhesive wear) and debris features (e.g., concentration (number), size, morphology, and composition), analyzes detection methods principles (e.g., offline: spectrograph and ferrograph, and online: optical method, inductive method, resistive-capacitive method, and acoustic method), reviews developments of online inductive methods ...


Erosion Degradation Characteristics Of A Linear Electro-Hydrostatic Actuator Under A High-Frequency Turbulent Flow Field, Yuan Li, Shaoping Wang, Mileta M. Tomovic, Chao Zhang 2018 Old Dominion University

Erosion Degradation Characteristics Of A Linear Electro-Hydrostatic Actuator Under A High-Frequency Turbulent Flow Field, Yuan Li, Shaoping Wang, Mileta M. Tomovic, Chao Zhang

Engineering Technology Faculty Publications

The paper proposes a performance degradation analysis model based on dynamic erosion wear for a novel Linear Electro-Hydrostatic Actuator (LEHA). Rather than the traditional statistical methods based on degradation data, the method proposed in this paper firstly analyzes the dominant progressive failure mode of the LEHA based on the working principle and working conditions of the LEHA. The Computational Fluid Dynamics (CFD) method, combining the turbulent theory and the micro erosion principle, is used to establish an erosion model of the rectification mechanism. The erosion rates for different port openings, under a time-varying flow field, are obtained. The piecewise linearization ...


Application Of Surface Treatments To Improve Fuel Efficiency Of Internal Combustion Engines, Amirabbas Akbarzadeh 2017 Louisiana State University and Agricultural and Mechanical College

Application Of Surface Treatments To Improve Fuel Efficiency Of Internal Combustion Engines, Amirabbas Akbarzadeh

LSU Master's Theses

To improve the tribological performance of contacting surfaces, different surface modification methods can be employed. Surface texturing and surface coating are examples of viable techniques developed for this purpose. Surface texturing involves creating micropatterns on the contacting surfaces while surface coating requires depositing a thin layer of a suitable material on the surface(s) to improve the component’s friction and wear characteristics. The performance of textured surfaces is affected by the geometric characteristic of textures.When dealing with surface coating parameters, the parameters of interests are the type of coating materials and their thicknesses.

The current study aims to ...


Tactile Discrimination Of Randomly Textured Surfaces: Effect Of Friction And Surface Parameters, Geetha Chimata, Christian J. Schwartz 2017 Iowa State University

Tactile Discrimination Of Randomly Textured Surfaces: Effect Of Friction And Surface Parameters, Geetha Chimata, Christian J. Schwartz

Mechanical Engineering Publications

The aim of the current study is to identify the physical factors that could potentially be indicative of the tactile discriminability of textured surfaces. To this end, the tactile discrimination sensitivity for fine randomly textured surfaces was evaluated and its relation to the surface parameters and the coefficient of friction was investigated. Discrimination tasks were performed using a two-interval forced choice technique and the mean probability of perceiving a difference was measured for pairwise combinations of six fine-grit abrasive papers. The surface roughness parameters of the abrasive papers were measured using a contact profilometer and scanning electron microscopy images helped ...


Silicon Carbide Materials Properties Selection For Mechanical Seal Faces, William Charles Hoskins 2017 University of Tennessee, Knoxville

Silicon Carbide Materials Properties Selection For Mechanical Seal Faces, William Charles Hoskins

Chancellor’s Honors Program Projects

No abstract provided.


Study Of The Temporal Characteristics Of Friction And Contact Behavior Encountered During Braille Reading, Matthew A. Darden, Christian J. Schwartz 2017 Iowa State University

Study Of The Temporal Characteristics Of Friction And Contact Behavior Encountered During Braille Reading, Matthew A. Darden, Christian J. Schwartz

Mechanical Engineering Publications

Beyond the sense of sight, the sense of touch is one of the primary ways that individuals experience their surrounding environment. Fundamentally understanding the relationship of skin-surface tribology and its elicited tactile attributes could provide a breakthrough in improving the ability to efficiently transmit tactile information to those who rely on the sense of touch to interact with their surroundings, such as the blind and visually impaired (BVI) community. The tactile language of braille has been adopted by the BVI community, employing configurations of raised dome-shape dots to convey what is ordinarily presented in text and image form. The coefficient ...


Modeling And Computation Of The Maximum Braking Energy Speed For Transport Category Airplanes, Nihad E. Daidzic 2017 AAR Aerospace Consulting, LLC

Modeling And Computation Of The Maximum Braking Energy Speed For Transport Category Airplanes, Nihad E. Daidzic

Journal of Aviation Technology and Engineering

Transport-category or FAR/CS 25 certified airplanes may occasionally become braking energy capacity limited. Such limitation may exist when heavy airplanes are departing airports at high-density altitudes, on relatively long runways, and/or possibly with some tailwind component. A maximum braking energy VMBE speed exists which may limit the maximum allowable takeoff decision/action speed V1. The ever-existing possibility of high-speed rejected takeoff in such conditions may also limit the airplane gross weight for declared available distances. To gain deeper insights and acquire better understanding of the topic, a theoretical model of the maximum braking energy and the related VMBE ...


Investigation Of An Axial Flow Rotary Valve Seal, Joseph K. Stieha 2017 University of Kentucky

Investigation Of An Axial Flow Rotary Valve Seal, Joseph K. Stieha

Theses and Dissertations--Mechanical Engineering

This thesis investigates potential materials to be used in the rotary sealing industry that provide low power loss and minimize cost. The studied rotary valve utilizes slots that act as timing valves to allow for flow axially, through the seal face, at particular times within a heat pump cycle. This investigation examines various combinations of multiple PTFE materials, plastics, and soft metals that have been proven to provide low friction coefficients. Leakage and wear requirements are stated for the future use of the rotary valve and are used to determine the effectiveness of sealing the fluid while examining the power ...


Parametric Investigation Of Soft-Body Penetration Into Parallel-Ridged Textured Surfaces For Tactile Applications, Thomas J. Wilde, Christian J. Schwartz 2016 Iowa State University

Parametric Investigation Of Soft-Body Penetration Into Parallel-Ridged Textured Surfaces For Tactile Applications, Thomas J. Wilde, Christian J. Schwartz

Mechanical Engineering Publications

The tribological interactions between skin and textured surfaces has profound impact on both the tactile perception of the product being used, as well as the functionality of the product with regards to friction coefficient. Previous work has shown that parallel-ridged textures have vastly different friction coefficients with regards to the direction of skin sliding, and that penetration of the skin into the voids between ridges not only add contact area but also potential for interlocking. The ability to model skin penetration into textural elements would prove to be very useful for predicting friction; however, the mechanics of the problem are ...


Tribological Testing And Analysis Of Ionic Liquids As Candidate Anti-Wear Additives For Next-Generation Engine Lubricants, William Charles Barnhill 2016 University of Tennessee - Knoxville

Tribological Testing And Analysis Of Ionic Liquids As Candidate Anti-Wear Additives For Next-Generation Engine Lubricants, William Charles Barnhill

Masters Theses

In this work, fourteen ionic liquids (ILs) were assayed as potential next-generation engine oil additives. After screening for corrosion, thermal stability and oil solubility, candidate additives were subjected to friction and wear tests in both boundary and mixed regime lubrication. While each IL demonstrated friction and wear reduction compared to base oil without any additives, oil miscible ILs tetraoctylphosphonium bis 2-ethylhexyl phosphate ([P8888][DEHP]) and trioctylammonium bis 2-ethylhexylphosphate ([N888H][DEHP]) were the best performers in bench tests with a XX% and XX% improvement in wear over the base oil respectively. Each of these ILs excellent solubility and superior performance was ...


Polytetraflouroethylene Thin Coatings For Tribological Applications, Samuel L. Jenkins 2016 University of Arkansas, Fayetteville

Polytetraflouroethylene Thin Coatings For Tribological Applications, Samuel L. Jenkins

Mechanical Engineering Undergraduate Honors Theses

Mechanical components with lower coefficients of friction decrease the amount of energy dissipated by the system due to friction. Coating these components would decrease the coefficients of friction between surfaces without sacrificing the strength of the components. A polytetrafluoroethylene (PTFE) layer adhered through a polydopamine (PDA) layer on a steel substrate will reduce the coefficient of friction on the substrate surface. This paper discusses different methods for attempting to increase the uniformity of the PDA layer as well as decrease the PDA coating time. Methods for increasing uniformity include using a particle disperser instead of a magnet stir rod, changing ...


Study Of Role Of Meniscus And Viscous Forces During Liquid-Mediated Contacts Separation, Prabin Dhital 2016 Minnesota State University Mankato

Study Of Role Of Meniscus And Viscous Forces During Liquid-Mediated Contacts Separation, Prabin Dhital

All Theses, Dissertations, and Other Capstone Projects

Menisci may form between two solid surfaces with the presence of an ultra-thin liquid film. When the separation operation is needed, meniscus and viscous forces contribute to an adhesion leading stiction, high friction, possibly high wear and potential failure of the contact systems, for instance microdevices, magnetic head disks and diesel fuel injectors. The situation may become more pronounced when the contacting surfaces are ultra-smooth and the normal load is small. Various design parameters, such as contact angle, initial separation height, surface tension and liquid viscosity, have been investigated during liquid-mediated contact separation. However, how the involved forces will change ...


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