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Full-Text Articles in Engineering

Novel Patterning Techniques To Improve Digital Image Correlation In Challenging Environments, Weston Craig Aug 2022

Novel Patterning Techniques To Improve Digital Image Correlation In Challenging Environments, Weston Craig

All Graduate Theses and Dissertations

A camera-based measurement technique called digital image correlation (DIC) is beneficial to measure displacement and strain in challenging environments (such as post-irradiation evaluation and high temperature environments) due to its non-contacting nature and ability to obtain measurements over multiple length scales. This technique requires a surface pattern which influences the measurement resolution and accuracy of the measurements. This thesis explores two novel patterning techniques to allow the use of DIC in more challenging environments:

The first is to determine if a pattern created from printed text can be used as a pattern in DIC. Native patterns are patterns already present ...


Nano-Enhanced Biolubricant In Sustainable Manufacturing: From Processability To Mechanisms, Yanbin Zhang, Hao Nan Li, Changhe Li, Chuanzhen Huang, Hafiz Muhammad Ali, Xuefeng Xu, Cong Mao, Wenfeng Ding, Xin Cui, Min Yang, Tianbiao Yu, Muhammad Jamil, Munish Kumar Gupta, Dongzhou Jia, Zafar Said Jun 2022

Nano-Enhanced Biolubricant In Sustainable Manufacturing: From Processability To Mechanisms, Yanbin Zhang, Hao Nan Li, Changhe Li, Chuanzhen Huang, Hafiz Muhammad Ali, Xuefeng Xu, Cong Mao, Wenfeng Ding, Xin Cui, Min Yang, Tianbiao Yu, Muhammad Jamil, Munish Kumar Gupta, Dongzhou Jia, Zafar Said

Friction

To eliminate the negative effect of traditional metal-working fluids and achieve sustainable manufacturing, the usage of nano-enhanced biolubricant (NEBL) is widely researched in minimum quantify lubrication (MQL) machining. It’s improved tool wear and surface integrity have been preliminarily verified by experimental studies. The previous review papers also concluded the major influencing factors of processability including nano-enhancer and lubricant types, NEBL concentration, micro droplet size, and so on. Nevertheless, the complex action of NEBL, from preparation, atomization, infiltration to heat transfer and anti-friction, is indistinct which limits preparation of process specifications and popularity in factories. Especially in the complex machining ...


Tribological Behavior Of Co-Textured Cylinder Liner-Piston Ring During Running-In, Chenwei Miao, Zhiwei Guo, Chengqing Yuan Jun 2022

Tribological Behavior Of Co-Textured Cylinder Liner-Piston Ring During Running-In, Chenwei Miao, Zhiwei Guo, Chengqing Yuan

Friction

The running-in of cylinder liner-piston rings (CLPRs) is the most important process that must be performed before a marine diesel engine can be operated. The quality of running-in directly affects the reliability of a CLPR. The surface texture of a CLPR has been proven to significantly affect its lubrication performance. In this study, the tribological behavior of a CLPR during running-in is investigated. Three types of surface textures are generated on the CLPR via laser processing: dimple texture on piston rings, groove texture on cylinder liners, and co-texture on both sides. Subsequently, a series of tests are performed on a ...


Investigation Into Gas Lubrication Performance Of Porous Gas Bearing Considering Velocity Slip Boundary Condition, Xiangbo Zhang, Shuiting Ding, Farong Du, Fenzhu Ji, Zheng Xu, Jiang Liu, Qi Zhang, Yu Zhou Jun 2022

Investigation Into Gas Lubrication Performance Of Porous Gas Bearing Considering Velocity Slip Boundary Condition, Xiangbo Zhang, Shuiting Ding, Farong Du, Fenzhu Ji, Zheng Xu, Jiang Liu, Qi Zhang, Yu Zhou

Friction

Porous gas bearings (PGBs) have a proactive application in aerospace and turbomachinery. This study investigates the gas lubrication performance of a PGB with the condition of velocity slip boundary (VSB) owing to the high Knudsen number in the gas film. The Darcy-Forchheimer laws and modified Navier-Stokes equations were adopted to describe the gas flow in the porous layer and gas film region, respectively. An improved bearing experimental platform was established to verify the accuracy of the derived theory and the reliability of the numerical analysis. The effects of various parameters on the pressure distribution, flow cycle, load capacity, mass flow ...


Effect Of Wear Debris On Fretting Fatigue Crack Initiation, Shengjie Wang, Tongyan Yue, Dagang Wang, Magd Abdel Wahab Jun 2022

Effect Of Wear Debris On Fretting Fatigue Crack Initiation, Shengjie Wang, Tongyan Yue, Dagang Wang, Magd Abdel Wahab

Friction

Both wear and fatigue occur in fretting condition, and they interact with one another during the whole process. Fretting fatigue is commonly analysed without considering the effect of wear in partial slip regime, although wear affects the lifetime of crack initiation. This paper investigates, for the first time, the effect of wear debris on fretting fatigue crack initiation. To investigate the effect of debris, first fretting wear characteristics in partial slip regime are analysed for loading conditions. Then, the effect of wear on fretting fatigue crack initiation is investigated using Ruiz parameters and critical plane methods without considering the debris ...


Incipient Sliding Of Adhesive Contacts, Francesc Pérez-Ràfols, Lucia Nicola Jun 2022

Incipient Sliding Of Adhesive Contacts, Francesc Pérez-Ràfols, Lucia Nicola

Friction

A model is proposed herein to investigate the incipient sliding of contacts in the presence of both friction and adhesion, where the interfacial response is modeled based on traction-separation laws. A Maugis-like parameter is defined to characterize the response in the tangential direction. Subsequently, the model is used to investigate the contact between a smooth cylinder and a flat body, where adhesion-friction interactions are strong. A range of behaviors are observed when a tangential displacement is imposed: When the parameter is low, the contact pressure exhibits a relatively constant profile; when it is high, a pressure spike is observed at ...


Water-Based Lubrication Of Niobium Nitride, Kaifei Miao, Jia Wang, Qiang Zhao, Kaiwen Wang, Mao Wen, Kan Zhang Jun 2022

Water-Based Lubrication Of Niobium Nitride, Kaifei Miao, Jia Wang, Qiang Zhao, Kaiwen Wang, Mao Wen, Kan Zhang

Friction

Water-based lubrication has attracted wide attention as an oil-free lubrication method owing to its greener and cleaner lubrication means. However, due to operating in the water environment, most moving parts would inevitably suffer from abrasion, rusting, and aging problems. Developing a novel solid-water composite system with ultra-low friction and wear will open new possibilities for innovative lubrication material research and development. Here, we first revealed the water-based lubrication behavior of a high-hardness niobium nitride coating (NbN). In a three-phase contact environment (water, air, and NbN), oxidation and hydrolytic reactions of NbN result in the formation of "colloidal solutions", containing Nb ...


Enhanced Tribological Properties Of Aligned Graphene-Epoxy Composites, Yuefeng Du, Zhenyu Zhang, Dong Wang, Lezhen Zhang, Junfeng Cui, Yapeng Chen, Mingliang Wu, Ruiyang Kang, Yunxiang Lu, Jinhong Yu, Nan Jiang Jun 2022

Enhanced Tribological Properties Of Aligned Graphene-Epoxy Composites, Yuefeng Du, Zhenyu Zhang, Dong Wang, Lezhen Zhang, Junfeng Cui, Yapeng Chen, Mingliang Wu, Ruiyang Kang, Yunxiang Lu, Jinhong Yu, Nan Jiang

Friction

The random distribution of graphene in epoxy matrix hinders the further applications of graphene-epoxy composites in the field of tribology. Hence, in order to fully utilize the anisotropic properties of graphene, highly aligned graphene-epoxy composites (AGEC) with horizontally oriented structure have been fabricated via an improved vacuum filtration freeze-drying method. The frictional tests results indicated that the wear rate of AGEC slowly increased from 5.19×10-6 mm3/(N·m) to 2.87×10-5 mm3/(N·m) with the increasing of the normal load from 2 to 10 N, whereas the friction coefficient (COF) remained a ...


Optimizing The Tribological Performance Of Dlc-Coated Nbr Rubber: The Role Of Hydrogen In Films, Changning Bai, Li Qiang, Bin Zhang, Kaixiong Gao, Junyan Zhang Jun 2022

Optimizing The Tribological Performance Of Dlc-Coated Nbr Rubber: The Role Of Hydrogen In Films, Changning Bai, Li Qiang, Bin Zhang, Kaixiong Gao, Junyan Zhang

Friction

Diamond-like carbon (DLC) films directly deposited on rubber substrate is undoubtedly one optimal option to improve the tribological properties due to its ultralow friction, high-hardness as well as good chemical compatibility with rubber. Investigating the relationship between film structure and tribological performance is vital for protecting rubber. In this study it was demonstrated that the etching effect induced by hydrogen incorporation played positive roles in reducing surface roughness of DLC films. In addition, the water contact angle (CA) of DLC-coated nitrile butadiene rubber (NBR) was sensitive to the surface energy and sp2 carbon clustering of DLC films. Most importantly ...


Experimental And Modelling Studies Of The Transient Tribological Behaviour Of A Two-Phase Lubricant Under Complex Loading Conditions, Xiao Yang, Lemeng Zhang, Denis J. Politis, Jie Zhang, Mohammad M. Gharbi, David Leyvraz, Liliang Wang Jun 2022

Experimental And Modelling Studies Of The Transient Tribological Behaviour Of A Two-Phase Lubricant Under Complex Loading Conditions, Xiao Yang, Lemeng Zhang, Denis J. Politis, Jie Zhang, Mohammad M. Gharbi, David Leyvraz, Liliang Wang

Friction

The transient tribological phenomenon and premature lubricant breakdown have been widely observed in metal forming, leading to excessive friction at the contact interfaces. In this research, the transient tribological behaviour of a two-phase lubricant were studied under complex loading conditions, featuring abrupt interfacial temperature, contact load, and sliding speed changes, thus representing the severe interfacial conditions observed in warm/hot metal forming applications. The strong experimental evidence indicates that the evolution of friction was attributed to the physical diminution and chemical decomposition effects. As such, a visco-mechanochemical interactive friction model was developed to accurately predict the transient tribological behaviour of ...


A Finite-Element-Aided Ultrasonic Method For Measuring Central Oil-Film Thickness In A Roller-Raceway Tribo-Pair, Pan Dou, Tonghai Wu, Zhaopeng Luo, Peiping Yang, Zhongxiao Peng, Min Yu, Tom Reddyhoff Jun 2022

A Finite-Element-Aided Ultrasonic Method For Measuring Central Oil-Film Thickness In A Roller-Raceway Tribo-Pair, Pan Dou, Tonghai Wu, Zhaopeng Luo, Peiping Yang, Zhongxiao Peng, Min Yu, Tom Reddyhoff

Friction

Roller bearings support heavy loads by riding on an ultra-thin oil film (between the roller and raceway), the thickness of which is critical as it reflects the lubrication performance. Ultrasonic interfacial reflection, which facilitates the non-destructive measurement of oil-film thickness, has been widely studied. However, insufficient spatial resolution around the rolling line contact zone remains a barrier despite the use of miniature piezoelectric transducers. In this study, a finite-element-aided method is utilized to simulate wave propagation through a three-layered structure of roller-oil-raceway under elastohydrodynamic lubrication (EHL) with nonlinear characteristics of the i) deformed curvature of the cylindrical roller and ii ...


Optimal Design Of Bacterial Carpets For Fluid Pumping, Minghao W. Rostami, Weifan Liu, Amy Buchmann, Eva Strawbridge, Longhua Zhao May 2022

Optimal Design Of Bacterial Carpets For Fluid Pumping, Minghao W. Rostami, Weifan Liu, Amy Buchmann, Eva Strawbridge, Longhua Zhao

Biology and Medicine Through Mathematics Conference

No abstract provided.


Experimental Characterization And Manufacture Of Polymer Nanocomposite Dielectric Coatings For High-Temperature Superconductor Applications, Jacob Ryan Mahon May 2022

Experimental Characterization And Manufacture Of Polymer Nanocomposite Dielectric Coatings For High-Temperature Superconductor Applications, Jacob Ryan Mahon

Theses and Dissertations

Increased implementation of high-temperature superconducting (HTS) power transmission has the potential to revolutionize the efficiency of electrical grids and help unlock a fully electric transportation infrastructure. Realizing the benefits of HTS systems has been impeded by a lack of available dielectric insulation materials that can 1) withstand the extreme cryogenic operating environment of superconductors and 2) demonstrate low temperature processing that is compatible with existing superconductor manufacturing methods. Solving this problem necessitates a high-performance dielectric material with multifunctional properties specifically suited for operation in HTS systems. A polyamide and silicon dioxide (PA/SiO2) nanocomposite material with exceptional thermal stability has ...


Monolithically Integrated Microscale Pressure Sensor On An Optical Fiber Tip [U.S. Patent Us11326970b2], Jeremiah C. Williams, Hengky Chandrahalim May 2022

Monolithically Integrated Microscale Pressure Sensor On An Optical Fiber Tip [U.S. Patent Us11326970b2], Jeremiah C. Williams, Hengky Chandrahalim

Faculty Publications

A passive microscopic Fabry-Pérot Interferometer (FPI) pressure sensor includes an optical fiber and a three-dimensional microscopic optical enclosure. The three-dimensional microscopic optical enclosure includes tubular side walls having lateral pleated corrugations and attached to a cleaved tip of the optical fiber to receive a light signal. An optically reflecting end wall is distally engaged to the tubular side walls to enclose a trapped quantity of gas that longitudinally positions the optically reflecting end wall in relation to ambient air pressure, changing a distance traveled by a light signal reflected back through the optical fiber.


Manual Material Handling Lift-Assist System For Occupational Exoskeleton, Erik Goes, Daniel Guthrie, Trevor Ward May 2022

Manual Material Handling Lift-Assist System For Occupational Exoskeleton, Erik Goes, Daniel Guthrie, Trevor Ward

Honors Capstones

It is no secret that lifting heavy objects is one of the premier causes of workplace injury, and the modern worker needs help to remain healthy. Workers need something they always have with them that makes their work safer as well as easier; our solution is an active lift-assist exoskeleton. The proposed exoskeleton design includes a military backpack exoskeleton frame, on which two actuators pull cables attached to end effectors that the operator will be holding. This system can adjust to conform to a wide variety of operator sizes, without restricting any of their range of motion. This leads to ...


Novel Mobility Device For Conjoined Twins, Allyson Bowgren May 2022

Novel Mobility Device For Conjoined Twins, Allyson Bowgren

Honors Capstones

This project provides a solution to a problem proposed by a pair of conjoined clients. With their desire to become fully independent, the clients need an improved mobility device. Being joined at the head, moving around was always difficult for them and their situation did not get any better after an accident left one of them immobile. Their current device was a decent and quick solution at the time it was first needed. However, since its conception the device quickly became obsolete, and they are now in need of a more effective device that allows them to travel easier. This ...


Fea Analysis On A Beam Of Hexacopter Drone Frame, Aicha Chahbi El Alaoui, Taymae Ben Messaoud May 2022

Fea Analysis On A Beam Of Hexacopter Drone Frame, Aicha Chahbi El Alaoui, Taymae Ben Messaoud

ME 4233/6233 Fundamentals of FEA

Our project covers the research made, a deep analysis, the structural design, modeling, and design of a hexa copter, which has six degrees of freedom. In order to improve the drone’s dynamics and efficiency, an analysis will be conducted on one beam constituting the drone using Abacus.


Inorganic Nanomaterial Lubricant Additives For Base Fluids, To Improve Tribological Performance: Recent Developments, Junhai Wang, Weipeng Zhuang, Wenfeng Liang, Tingting Yan, Ting Li, Lixiu Zhang, Shu Li May 2022

Inorganic Nanomaterial Lubricant Additives For Base Fluids, To Improve Tribological Performance: Recent Developments, Junhai Wang, Weipeng Zhuang, Wenfeng Liang, Tingting Yan, Ting Li, Lixiu Zhang, Shu Li

Friction

In this paper, we review recent research developments regarding the tribological performances of a series of inorganic nano-additives in lubricating fluids. First, we examine several basic types of inorganic nanomaterials, including metallic nanoparticles, metal oxides, carbon nanomaterials, and "other" nanomaterials. More specifically, the metallic nanoparticles we examine include silver, copper, nickel, molybdenum, and tungsten nanoparticles; the metal oxides include CuO, ZnO, Fe3O4, TiO2, ZrO2, Al2O3, and several double-metal oxides; the carbon nanomaterials include fullerene, carbon quantum dots, carbon nanotubes, graphene, graphene oxides, graphite, and diamond; and the "other" nanomaterials include metal sulfides ...


Design Of Bidirectional Frictional Behaviour For Tactile Contact Using Ellipsoidal Asperity Micro-Textures, Dmitrii Sergachev, David Matthews, Emile Van Der Heide May 2022

Design Of Bidirectional Frictional Behaviour For Tactile Contact Using Ellipsoidal Asperity Micro-Textures, Dmitrii Sergachev, David Matthews, Emile Van Der Heide

Friction

Tactile perception and friction can be modified by producing a deterministic surface topography. Change of surface feature arrangement and texture symmetry can produce an anisotropic frictional behaviour. It is generally achieved through skin hysteresis by promoting its deformation. This work investigates whether a bidirectional friction can be created with microscale ellipsoidal asperity textures, thus relying on the adhesive component of friction. For this purpose, four textured samples with various asperity dimensions were moulded with a silicone rubber having an elastic modulus comparable to that of the skin. Coefficient of friction measurements were conducted in-vivo in two sliding directions with a ...


Tribological Performance Of Various Metal-Doped Carbon Dots As Water-Based Lubricant Additives And Their Potential Application As Additives Of Poly(Ethylene Glycol), Weiwei Tang, Xuejun Zhu, Yufeng Li May 2022

Tribological Performance Of Various Metal-Doped Carbon Dots As Water-Based Lubricant Additives And Their Potential Application As Additives Of Poly(Ethylene Glycol), Weiwei Tang, Xuejun Zhu, Yufeng Li

Friction

Advances in nano-lubricant additives are vital to the pursuit of energy efficiency and sustainable development. Carbon dots (CDs) have been widely investigated in the domain of lubricant additives owing to their extraordinary tribological properties, in particular, their friction-reducing and anti-wear properties. Metal-doped CDs are a new type of CDs, and their friction-reducing and anti-wear properties are attracting increasing attention. Therefore, a series of CDs doped with various divalent metal ions have been successfully synthesized via one-pot pyrolysis. The tribological properties of the synthesized CDs as water-based lubricant additives are in the following order: Zn-CDs > Cu-CDs >> Mg-CDs > Fe-CDs > U-CDs. Specifically, adding ...


Mono-Dispersed Ag Nanoparticles Decorated Graphitic Carbon Nitride: An Excellent Lubricating Additive As Ppesk Composite Film, Beibei Chen, Mengjie Zhang, Kan Zhang, Zhe Dong, Jiaye Li, Gai Zhao May 2022

Mono-Dispersed Ag Nanoparticles Decorated Graphitic Carbon Nitride: An Excellent Lubricating Additive As Ppesk Composite Film, Beibei Chen, Mengjie Zhang, Kan Zhang, Zhe Dong, Jiaye Li, Gai Zhao

Friction

Studies show that two dimensional (2D) nanomaterial and its hybrid have a great promise in tribology for the special laminar microstructure. However, the majority of performed investigations about 2D graphitic carbon nitride (g-C3N4) nanosheets are most focused on energy storage, catalysis, adsorption, rarely tribology. In the present study, g-C3N4 supporting mono-dispersed Ag nanoparticle hybrid (g- C3N4/Ag) is prepared, and its microstructure and chemical composition are determined. More specifically, the tribological performance as the lubricating additive of poly phthalazinone ether sulfone ketone (PPESK) composite is investigated using the ball-on-disc friction tester ...


Novel Three-Body Nano-Abrasive Wear Mechanism, Ruling Chen, Shaoxian Li May 2022

Novel Three-Body Nano-Abrasive Wear Mechanism, Ruling Chen, Shaoxian Li

Friction

Current three-body abrasive wear theories are based on a macroscale abrasive indentation process, and these theories claim that material wear cannot be achieved without damaging the hard mating surface. In this study, the process of three-body nano-abrasive wear of a system including a single crystalline silicon substrate, an amorphous silica cluster, and a polyurethane pad, based on a chemical mechanical polishing (CMP) process, is investigated via molecular dynamics simulations. The cluster slid in a suspended state in smooth regions and underwent rolling impact in the asperity regions of the silicon surface, realizing non-damaging monoatomic material removal. This proves that indentation-plowing ...


Structure, Tribological Properties, And The Growth Mechanism Of In-Situ Generated Tic In Titanium Cermet, Xiaolei Sun, Yong Luo, Junyang Wang, Qingliang Wang, Jianghao Qiao, Andrew Beadling, Michael Bryant, Zhongmin Jin May 2022

Structure, Tribological Properties, And The Growth Mechanism Of In-Situ Generated Tic In Titanium Cermet, Xiaolei Sun, Yong Luo, Junyang Wang, Qingliang Wang, Jianghao Qiao, Andrew Beadling, Michael Bryant, Zhongmin Jin

Friction

Titanium cermet combining metallic toughness with ceramic wear resistance has been proven to be a potential candidate for implanted joint material. In this work, titanium cermet was synthesized by means of the elevated temperature solid carburizing technology. The Ti13Nb13Zr alloy surface was found to be converted into TiC ceramic layer combined with a carbon strengthened diffusion zone underneath. The overall thickness of the carburized region grew to about 100 μm after 120 min carburization at 1,500 K. In order to clarify the growth behaviors of TiC ceramic layer, a growth mechanism is proposed. At the ...


Comprehensive Review Of Tribometer Dynamics—Cycle-Based Data Analysis And Visualization, Josef Prost, Guido Boidi, Thomas Lebersorger, Markus Varga, Georg Vorlaufer May 2022

Comprehensive Review Of Tribometer Dynamics—Cycle-Based Data Analysis And Visualization, Josef Prost, Guido Boidi, Thomas Lebersorger, Markus Varga, Georg Vorlaufer

Friction

Tribologists often rely on triboexperiments to investigate factors that affect a tribosystem. The inherent dynamic behavior of the respective tribometer setups and its effect on data interpretation remain often unknown. In this study, a comprehensive analysis of sensor data obtained from lubricated and dry triboexperiments is performed. Data are generated on a pin-on-disc test rig with a silicon nitride ball on a steel disc contact with a rotation frequency of ~3 Hz. High-speed acquisition of sensor data up to 5 kHz is performed to resolve changes in the data within individual cycles. The characteristic frequencies of the system and their ...


Experimental Investigation Of Granular Friction Behaviors During Reciprocating Sliding, Xuejie Zhang, Wei Sun, Wei Wang, Kun Liu May 2022

Experimental Investigation Of Granular Friction Behaviors During Reciprocating Sliding, Xuejie Zhang, Wei Sun, Wei Wang, Kun Liu

Friction

Granular friction behaviors are crucial for understanding the ubiquitous packing and flow phenomena in nature and industrial production. In this study, a customized experimental apparatus that can simultaneously measure the time history of normal and tangential forces on the inside-shearing unit is employed to investigate the granular friction behaviors during a linear reciprocating sliding process. It is observed that the evolution behaviors of two normal forces distributed separately on the shearing unit can qualitatively reflect the effects of the force chain network. During the half-loop of the reciprocating sliding, the total normal force, which indicates the load-bearing capacity of the ...


Dynamic Friction Energy Dissipation And Enhanced Contrast In High Frequency Bimodal Atomic Force Microscopy, Xinfeng Tan, Dan Guo, Jianbin Luo May 2022

Dynamic Friction Energy Dissipation And Enhanced Contrast In High Frequency Bimodal Atomic Force Microscopy, Xinfeng Tan, Dan Guo, Jianbin Luo

Friction

Dynamic friction occurs not only between two contact objects sliding against each other, but also between two relative sliding surfaces several nanometres apart. Many emerging micro- and nano-mechanical systems that promise new applications in sensors or information technology may suffer or benefit from noncontact friction. Herein we demonstrate the distance-dependent friction energy dissipation between the tip and the heterogeneous polymers by the bimodal atomic force microscopy (AFM) method driving the second order flexural and the first order torsional vibration simultaneously. The pull-in problem caused by the attractive force is avoided, and the friction dissipation can be imaged near the surface ...


Tuning Of Frictional Properties In Torsional Contact By Means Of Disk Grading, Gianluca Costagliola, Federico Bosia, Nicola M Pugno May 2022

Tuning Of Frictional Properties In Torsional Contact By Means Of Disk Grading, Gianluca Costagliola, Federico Bosia, Nicola M Pugno

Friction

The contact of two surfaces in relative rotating motion occurs in many practical applications, from mechanical devices to human joints, displaying an intriguing interplay of effects at the onset of sliding due to the axisymmetric stress distribution. Theoretical and numerical models have been developed for some typical configurations, but work remains to be done to understand how to modify the emergent friction properties in this configuration. In this paper, we extend the two-dimensional (2D) spring-block model to investigate friction between surfaces in torsional contact. We investigate how the model describes the behavior of an elastic surface slowly rotating over a ...


Automated Robotic Light Bulb Testing Platform, Agha I. Akram, Muhammad Ali Ummy May 2022

Automated Robotic Light Bulb Testing Platform, Agha I. Akram, Muhammad Ali Ummy

Publications and Research

The main purpose of this project is to create a functional prototype of a multilayered system that incorporates aspects of electrical, mechanical, and computer engineering technology. The main objective of the system is to be able to determine whether a light bulb is working or not. The building blocks of this system are a robotic arm that is able to slide along a rail (for added mobility), a conveyor belt, and an electromechanical device that holds and tests light bulbs. Initially, the robot arm picks up a light bulb and places it into the holder which then tests it. A ...


Hinged Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors [Us Patent Us11320596b2], Jeremiah C. Williams, Hengky Chandrahalim May 2022

Hinged Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors [Us Patent Us11320596b2], Jeremiah C. Williams, Hengky Chandrahalim

Faculty Publications

A passive microscopic Fabry-Pérot Interferometer (FPI) sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of the optical fighter using a two-photon polymerization process on a photosensitive polymer by a three-dimensional micromachining device. The three-dimensional microscopic optical structure having a hinged optical layer pivotally connected to a distal portion of a suspended structure. A reflective layer is deposited on a mirror surface of the hinged optical layer while in an open position. The hinged optical layer is subsequently positioned in the closed position to align the mirror surface to at least partially reflect a light signal back ...


Efficient Energy Harvesting With Applications In Vibration And Implantable Biosensors, Mohammad Atmeh May 2022

Efficient Energy Harvesting With Applications In Vibration And Implantable Biosensors, Mohammad Atmeh

Mechanical Engineering Theses

The world has stepped into the fourth industrial revolution in many ways such as using the internet of things (IoT) in various applications, and removing the rechargeable power sources seeking for batteryless systems. Since energy is widely abundant around us and it is going to waste, numerous of recent studies have been conducted to propose sustainable solutions to harvest the free ambient power from the surrounding and convert it into electricity. Heat energy, kinetic energy, and radio waves are examples of these potentially harvestable energy sources. Mechanical vibrations represent one of the most plentiful forms of kinetic energy that can ...