Mechanical Engineering Commons^™

A Novel Approach For Real-Time Quality Monitoring In Machining Of Aerospace Alloy Through Acoustic Emission Signal Transformation For Dnn, David Adeniji, Kyle Oligee, Julius Schoop

Mechanical Engineering Faculty Publications

Gamma titanium aluminide (γ-TiAl) is considered a high-performance, low-density replacement for nickel-based superalloys in the aerospace industry due to its high specific strength, which is retained at temperatures above 800 °C. However, low damage tolerance, i.e., brittle material behavior with a propensity to rapid crack propagation, has limited the application of γ-TiAl. Any cracks introduced during manufacturing would dramatically lower the useful (fatigue) life of γ-TiAl components, making the workpiece surface’s quality from finish machining a critical component to product quality and performance. To address this issue and enable more widespread use of γ-TiAl, this research aims to develop a …

A Novel Approach For Real-Time Quality Monitoring In Machining Of Aerospace Alloy Through Acoustic Emission Signal Transformation For Dnn, David Adeniji, Kyle Oligee, Julius Schoop

Mechanical Engineering Faculty Publications

Gamma titanium aluminide (γ-TiAl) is considered a high-performance, low-density replacement for nickel-based superalloys in the aerospace industry due to its high specific strength, which is retained at temperatures above 800◦C. However, low damage tolerance, i.e., brittle material behavior with a propensity to rapid crack propagation, has limited the application of γ-TiAl. Any cracks introduced during manufacturing would dramatically lower the useful (fatigue) life of γ-TiAl components, making the workpiece surface’s quality from finish machining a critical component to product quality and performance. To address this issue and enable more widespread use of γ-TiAl, this research aims to develop a real-time …

Matrix Acidizing In Carbonate Formations, Ofelia Gomez Chacon, Maysam Pournik

Mechanical Engineering Faculty Publications

Matrix acidizing in carbonate reservoirs is a process that has been long used to increase productivity in oil and gas producing formations. The main goal is to create wormholes that bypass the damage in the formation. Hydrochloric acid (HCl) is the main acid used for this; however, it has several disadvantages that affect the success of these treatments. Its high reaction rate, inability to divert, and corrosive nature are a few of the reasons why research in this area has focused on finding alternative fluids. This paper discusses studies on successful alternatives to HCl. It has been observed that emulsified …

Spatters And Spills: Spreading Dynamics For Partially Wetting Droplets, Sylvia C. L. Durian, Sam Dillavou, Kwame Markin, Adrian Portales, Bryan O. Torres Maldonado, William T. M. Irvine, Paulo E. Arratia, Douglas J. Durian

Mechanical Engineering Faculty Publications

We present a solvable model inspired by dimensional analysis for the time-dependent spreading of droplets that partially wet a substrate, where the spreading eventually stops and the contact angle reaches a nonzero equilibrium value. We separately consider small droplets driven by capillarity and large droplets driven by gravity. To explore both regimes, we first measure the equilibrium radius vs a comprehensive range of droplet volumes for four household fluids, and we compare the results with predictions based on minimizing the sum of gravitational and interfacial energies. The agreement is good and gives a reliable measurement of an equilibrium contact angle …

Vision And Radar Steering Reduces Agricultural Sprayer Operator Stress Without Compromising Steering Performance, Travis A. Burgers, Kelly J. Vanderwerff

Mechanical Engineering Faculty Publications

Self-propelled agricultural sprayer operators work an average of 15 h d^-1 in peak season, and steering is the task that causes the operator the most stress because of the large number of stimuli involved. Automatic guidance systems help reduce stress and fatigue for operators by allowing them to focus on tasks other than steering. Physiological signals like skin conductance (electrodermal activity, EDA) change with stress and can be used to identify stressful events. The objective of this study was to determine if using a commercially available vision and radar guidance system (VSN®, Raven Industries) reduces agricultural sprayer operators’ stress …

Antagonistic Co-Contraction Can Minimize Muscular Effort In Systems With Uncertainty, Anne D. Koelewijn, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Muscular co-contraction of antagonistic muscle pairs is often observed in human movement, but it is considered inefficient and it can currently not be predicted in
simulations where muscular effort or metabolic energy are minimized. Here, we investigated the relationship between minimizing effort and muscular co-contraction
in systems with random uncertainty to see if muscular co-contraction can minimize effort in such system. We also investigated the effect of time delay in the muscle, by varying the time delay in the neural control as well as the activation time constant.We solved optimal control problems for a one-degree-of-freedom pendulum actuated by two identical …

A Physics-Based Model For Frost Buildup Under Turbulent Flow Using Direct Numerical Simulations, ‪Nadim Zgheib, N. Farzaneh, S. Balachandar, S. A. Sherif

Mechanical Engineering Faculty Publications

We present a new model for frost buildup under turbulent (and laminar) flow using direct numerical simulations. The physical model consists of two layers, the air and the frost. The air layer is fully resolved and consists of solving for the velocity, temperature, and vapor mass fraction fields. The frost layer thickness is resolved using conservation of mass and energy. Both phases are dynamically coupled using the immersed boundary method. Three-dimensional simulations are conducted in an open-channel configuration. A number of challenges need to be overcome to make these simulations feasible. First, to enforce far-field conditions of zero …

Efficient Near Infrared To Visible Light Upconversion From Er/Yb Codoped Pvdf Fibrous Mats Synthesized Using A Direct Polymer Doping Technique, Saptasree Bose, Jack Ryan Summers, Bhupendra B. Srivastava, Victoria Padilla-Gainza, Manuel Peredo, Carlos Trevino De Leon, Bryan Hoke, Santosh K. Gupta, Karen Lozano

Mechanical Engineering Faculty Publications

Highlights

• Direct Rare Earth doping in PVDF Polymer to overcome powder limitation.

• PVDF Fiber with smooth and defect free texture designed by Forcespinning.

• Doping Enhances Beta fraction of PVDF without affecting thermal Stability.

• Efficient upconversion of NIR into visible light in PVDF:Yb3+,Er3+ fibrous mats.

• Two-Photon absorption for both green and red upconversions.

Abstract

Upconverting-materials are capable of converting near infra-red (NIR) excitation into lower wavelengths. These materials could have a myriad of promising potential applications. However, in some areas, its use has been hindered by its low upconversion luminescence (UCL) efficiency and processing/handling disadvantages from luminescent materials in powder form. …

Numerical Investigation On The Effect Of Spectral Radiative Heat Transfer Within An Ablative Material, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

The spectral radiative heat flux could impact the material response. In order to evaluate it, a coupling scheme between KATS - MR and P1 approximation model of radiation transfer equation (RTE) is constructed and used. A Band model is developed that divides the spectral domain into small bands of unequal widths. Two verification studies are conducted: one by comparing the simulation computed by the Band model with pure conduction results and the other by comparing with similar models of RTE. The comparative results from the verification studies indicate that the Band model is computationally efficient and can be used to …

Force And Torque Model Sensitivity And Coarse Graining For Bedload-Dominated Sediment Transport, Liheng Guan, Jorge Salinas, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

We present results from Euler–Lagrange simulations of turbulent flow over an erodible monodisperse bed of particles at a shear Reynolds number of R e τ = 180 . The Galileo number G a and the ratio of Shields to the critical Shields number Θ / θ c r were varied in the range 11.4 to 29.8 and 1.32 to 5.98, respectively. Two drag force models were investigated along with the influence of lift, particle rotation, and tangential collision forces for each model. Both models give similar results as far as mean particle flux and Shields stress are concerned, however we …

Subharmonic Resonance Of One Fourth Order Of Electrostatically Actuated Mems Circular Plates: Amplitude-Frequency Response, Dumitru Caruntu, Julio Beatriz, Miguel Martinez

Mechanical Engineering Faculty Publications

This work deals with the amplitude-frequency response subharmonic resonance of 1/4 order of electrostatically actuated circular plates. The method of multiple scales is used to model the hard excitations and to predict the response. This work predicts that the steady state solutions are zero amplitude solutions, and non-zero amplitude solutions which consist of stable and unstable branches. The effects of parameters such as voltage and damping on the response are predicted. As the voltage increases, the non-zero amplitude solutions are shifted to lower frequencies. As the damping increases, the non-zero steady-state amplitudes are shifted to higher amplitudes, so larger initial …

Forcespun Polyvinylpyrrolidone/Copper And Polyethylene Oxide/Copper Composite Fibers And Their Use As Antibacterial Agents, Md Toukir Hasan, Ramiro Gonzalez, Ari Alexis Munoz, Luis Materon, Jason Parsons, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

Copper nanoparticles (CuNPs) embedded in polyvinylpyrrolidone (PVP) and polyethylene oxide (PEO) fiber-matrices were prepared through centrifugal spinning of PVP/ethanol and PEO/aqueous solutions, respectively. The prime focus of the current study is to investigate the antibacterial activity of composite fibers against Escherichia coli (E. coli) and Bacillus cereus (B. cereus) bacteria. During the fiber formation, the centrifugal spinning parameters such as spinneret rotational speed, spinneret to collector distance, and relative humidity were carefully chosen to obtain long and continuous fibers. The structural and morphological analyses of both composite fibers were investigated using scanning electron microscopy, X-ray diffraction, …

Optimal Tracking In Switched Systems With Free Final Time And Fixed Mode Sequence Using Approximate Dynamic Programming, Tohid Sardarmehni, Xingyong Song

Mechanical Engineering Faculty Publications

Optimal tracking in switched systems with fixed mode sequence and free final time is studied in this article. In the optimal control problem formulation, the switching times and the final time are treated as parameters. For solving the optimal control problem, approximate dynamic programming (ADP) is used. The ADP solution uses an inner loop to converge to the optimal policy at each time step. In order to decrease the computational burden of the solution, a new method is introduced, which uses evolving suboptimal policies (not the optimal policies), to learn the optimal solution. The effectiveness of the proposed solutions is …

Numerical Study Of Fully Coupled Fluid-Structure Interaction Of Stented Ureter By Varying The Stent Side-Holes, Erick Martinez, Ben Xu, Jianzhi Li, Yingchen Yang

Mechanical Engineering Faculty Publications

Ureteral stents are a measure used for many medical issues involving urology, such as kidney stones or kidney transplants. The purpose of applying stents is to help relieve the urine flow while the ureter is either blocked or trying to close itself, which creates blockages. These ureteral stents, while necessary, cause pain and discomfort to patients due to them being a solid that moves around inside the patients’ body. The ureter normally moves urine to the bladder through peristaltic forces. Due to the ureter being a hyperelastic material, these peristaltic forces cause the ureter to deform easily, making it necessary …

Centrifugal Spinning And Characterization Of Co3o4 Coated Carbon Fibers, J. Ayala, D. Ramirez, Elizabeth M. Fletes, Helia Magali Morales, Jason Parsons, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

Centrifugally spun polyacrylonitrile (PAN) microfibers surface-coated with Co3O4 nanoparticles (NPs) were prepared as precursors to produce coated Co3O4 carbon-composite fibers. The Co3O4/C composite fibers were obtained through a staged heating process during which the Co3O4PAN precursor fibers were stabilized over four hours at 200 °C, and subsequently the stabilized fibers were carbonized for six hours at 600 °C. The synthesis process presented in this work provides an effective strategy for the fabrication of surface coated-fiber materials, including composite fibers with good structure and morphology. The characterization of the Co3O4/C composite fibers was performed using SEM, EDS, XPS, XRD …

Piezoelectric Properties Of Pvdf-Zn2geo4 Fine Fiber Mats, Fariha Rubaiya, Swati Mohan, Bhupendra B. Srivastava, Horacio Vasquez, Karen Lozano

Mechanical Engineering Faculty Publications

The current paper presents the development and characterization of polyvinylidene fluoride (PVDF)-Zn₂GeO₄ (ZGO) fine fiber mats. ZGO nanorods (NRs) were synthesized using a hydrothermal method and incorporated in a PVDF solution to produce fine fiber mats. The fiber mats were prepared by varying the concentration of ZGO NRs (1.25–10 wt %) using the Forcespinning^® method. The developed mats showed long, continuous, and homogeneous fibers, with average fiber diameters varying from 0.7 to 1 µm, depending on the ZGO concentration. X-ray diffraction spectra depicted a positive correlation among concentration of ZGO NRs and strengthening of the beta …

Minireview On Self-Healing Polymers: Versatility, Application, And Prospects, Md. Wasikur Rahman, Nawrin Rahman Shefa

Mechanical Engineering Faculty Publications

Nature is blessed with self-healing properties. Mimicking nature is a traditional practice to innovate new classes of materials for researchers. In this practice, researchers made a revolutionary approach to innovate self-healing polymer (SHP) that can be used to treat damage-related losses. Different SHPs with various properties have been developed for a wide range of applications. SHPs unlocked the key to the taste of real life through their application and versatility in the sectors close to our day-by-day life of this age and the near future. In this study, we reviewed the scopes and prospects of the application of SHPs owing …

Electrostatic Flocking Of Salt-Treated Microfibers And Nanofiber Yarns For Regenerative Engineering, Alec Mccarthy, Kossi Loic M. Avegnon, Phil A. Holubeck, Demi Brown, Anik Karan, Navatha Shree Sharma, Johnson V. John, Shelbie Weihs, Jazmin Ley, Jingwei Xie

Mechanical Engineering Faculty Publications

Electrostatic flocking is a textile technology that employs a Coulombic driving force to launch short fibers from a charging source towards an adhesive-covered substrate, resulting in a dense array of aligned fibers perpendicular to the substrate. However, electrostatic flocking of insulative polymeric fibers remains a challenge due to their insufficient charge accumulation. We report a facile method to flock electrostatically insulative poly(ε-caprolactone) (PCL) microfibers (MFs) and electrospun PCL nanofiber yarns (NFYs) by incorporating NaCl during pre-flock processing. Both MF and NFY were evaluated for flock functionality, mechanical properties, and biological responses. To demonstrate this platform's diverse applications, standalone flocked NFY …

Liquid Fuel Oil Produced From Plastic Based Medical Wastes By Thermal Cracking, Shahriar Bin Rasul, Uday Som, Md. Shameem Hossain, Md. Wasikur Rahman

Mechanical Engineering Faculty Publications

The present work is an effort to produce liquid fuel oil from plastic based medical wastes through thermal cracking process under oxidizing conditions. The mixed plastics from medical wastes were considered as a feedstock, shredded into small pieces and heated at 773 ± 10 K for 40 min with a heating rate of 20 K/min in a batch reactor for thermal cracking process. The feedstock was characterized by proximate and ultimate analysis along with thermogravimetric investigation. Moreover, chemical compositions of the liquid fuel oil were examined by FTIR and GC–MS spectroscopy. The properties of liquid product were also examined and …

Two-Dimensional Modeling Of Nonlinear Dynamics Of Forcespinning Jet Formation, Dumitru I. Caruntu, Simon Padron, Karen Lozano

Mechanical Engineering Faculty Publications

Forcespinning is a novel method that makes use of centrifugal forces to produce nanofibers rapidly and at high yields. To improve and enhance the forcespinning production method, a 2D computational forcespinning inviscid fluid dynamics model is developed. Two models, namely, time-independent and time-dependent, are obtained in order to investigate the effects of various parameters on fiber forcespinning formation (trajectory, jet diameter, tangential velocity). The fluid dynamics equations are solved using the method of multiple scales along with the finite difference method and including slender-jet theory assumptions. It is important to produce jets with small diameters in the micro- and nanorange. …

Fully Coupled Internal Radiative Heat Transfer For The 3d Material Response Of Heat Shield, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

The radiative transfer equation (RTE) is strongly coupled to the material response code KATS. A P-1 approximation model of RTE is used to account for radiation heat transfer within the material. First, the verification of the RTE model is performed by comparing the numerical and analytical solutions. Next, the coupling scheme is validated by comparing the temperature profiles of pure conduction and conduction coupled with radiative emission. The validation study is conducted on Marschall et al. cases (radiant heating, arc-jet heating, and space shuttle entry), 3D Block, 2D IsoQ sample, and Stardust Return Capsule. The validation results agree well for …

Incorporating A Mid-Semester Project To Evaluate Communication, And Leadership Skills For Undergraduate Engineering Students In The Statics/Strength Of Materials Course: A Comparative Assessment Before And During Covid-19, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this research study, a Popsicle-bridge project was assigned to a cohort of undergraduate engineering students enrolled in a Statics and Strength of Materials Course to enhance technical, communication, and leadership skills when working in a group setting. In most undergraduate engineering courses, the technical content is primarily emphasized for the academic development of the student. However, a practicing engineer must be able to possess and apply communication and leadership skills, which are often excluded from the existing curriculum. The first assessment of this project was completed with a cohort of 85 students in the Fall of 2019 before the …

Quality Mentorship Matters: An Innovative Approach To Supporting Student Success In Engineering Undergraduate Research, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this research study, the authors developed a new model of mentorship for faculty members to engage and support their group of students conducting undergraduate engineering research. Research efforts attest that mentoring undergraduate students is a critical role that can dramatically enhance student academic and personal outcomes. This finding is magnified in the context of STEM related disciplines, such as engineering, where efforts to pro-actively diversify the workforce are taking shape. Yet, not every form of faculty-student mentorship is proven to be effective, particularly when faculty conceal forms of knowledge and information regarding internship/employment resources, departmental and research opportunities, curriculum …

Scaffolding Student Success: Developing A Culturally Responsive Approach To Support Underrepresented Minorities In Engineering Undergraduate Research, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this research study, a scaffolding technique is implemented in undergraduate research to cultivate and enhance engineering related aptitudes and stimulate additional experience that will allow underrepresented minority students to fully engage in communication and leadership roles post-graduation. Developing and supporting the growth of underrepresented minorities as leaders who make significant innovative contributions to the global and interconnected scientific society requires awareness of contextual issues that shape their educational experiences and a commitment to enact on a framework that blends technical, communication, and leadership skills in undergraduate engineering education. In the context of this four year study, a total of …

Investigation Of Theoretical Scaling Laws Using Large Eddy Simulations For Airborne Spreading Of Viral Contagion From Sneezing And Coughing, K. Liu, M. Allahyari, J. Salinas, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

Using a set of large eddy point-particle simulations, we explore the fluid dynamics of an ejected puff resulting from a cough/sneeze. The ejection contains over 61 000 potentially virus-laden droplets at an injection Reynolds number of about 46 000, comparable to an actual cough/sneeze. We observe that global puff properties, such as centroid, puff volume, momentum, and buoyancy vary little across realizations. Other properties, such as maximum extent, shape, and edge velocity of the puff, may exhibit substantial variation. In many realizations, a portion of the puff splits off and advances along a random direction, while keeping airborne droplet nuclei …

Energy Harvesting Device For Powering Onboard Condition Monitoring Modules In Rail Service, Martin Amaro Jr., Constantine Tarawneh, Heinrich D. Foltz, Roberto A. Garcia

Mechanical Engineering Faculty Publications

Rail transportation plays an important role in today’s economy by delivering a large quantity of goods and passengers to various locations throughout North America in an economic and efficient manner. Bearing failure is one of the leading causes of derailments that result in significant capital loss and in extreme cases tragic human loss. The two widely used bearing health monitoring systems are the Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). These systems are reactive in nature and only give alerts when the bearings are nearing failure. To supplant that, a prototype wireless onboard condition monitoring system …

Adsorption Of Manganese Ions From Aqueous Solution By Using Manganese Oxide Coated Zeolite, Md. Wasikur Rahman, Huei Ruey Ong, Wendy Yin Jou Kong, Hamidah Abdullah, Md. Maksudur Rahman Khan

Mechanical Engineering Faculty Publications

Manganese oxide coated zeolite (MOCZ) has been demonstrated in the present issue as a potential adsorbent for the removal of manganese (Mn2+) from Mn2+ containing aqueous solution by batch adsorption process. The adsorption capacity of the as-prepared MOCZ was determined over the parameters of contact time, adsorbent dosage, pH and Mn2+ concentration. Surface properties of the MOCZ were analyzed by Brunauer–Emmett–Teller, X-ray diffraction and field emission scanning electron microscopy. Results showed that MOCZ has a high degree of crystallinity and the surface of MOCZ is mainly vernadite (γMnO2) with a specific surface area and average pore diameter of 39.9 m2 …

Peering Inside A Cough Or Sneeze To Explain Enhanced Airborne Transmission Under Dry Weather, Kai Liu, Majid Allahyari, Jorge S. Salinas, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

High-fidelity simulations of coughs and sneezes that serve as virtual experiments are presented, and they offer an unprecedented opportunity to peer into the chaotic evolution of the resulting airborne droplet clouds. While larger droplets quickly fall-out of the cloud, smaller droplets evaporate rapidly. The non-volatiles remain airborne as droplet nuclei for a long time to be transported over long distances. The substantial variation observed between the different realizations has important social distancing implications, since probabilistic outlier-events do occur and may need to be taken into account when assessing the risk of contagion. Contrary to common expectations, we observe dry ambient …

A Model-Based Approach To Predict Neuromuscular Control Patterns That Minimize Acl Forces During Jump Landing, Dieter Heinrich, Antonie J. Van Den Bogert, Robert Csapo, Werner Nachbauer

Mechanical Engineering Faculty Publications

Jump landing is a common situation leading to knee injuries involving the anterior cruciate ligament (ACL) in sports. Although neuromuscular control is considered as a key injury risk factor, there is a lack of knowledge regarding optimum control strategies that reduce ACL forces during jump landing. In the present study, a musculoskeletal model-based computational approach
is presented that allows identifying neuromuscular control patterns that minimize ACL forces during jump landing. The approach is demonstrated for a jump landing maneuver in downhill skiing, which is one out of three main injury mechanisms in competitive skiing.

Aloe Vera Extract-Based Composite Nanofibers For Wound Dressing Applications, Raul Barbosa, Alexa Villarreal, Cristobal Rodriguez, Heriberto De Leon, Robert Gilkerson, Karen Lozano

Mechanical Engineering Faculty Publications

Natural, biocompatible, and biodegradable composite nanofibers made of Aloe vera extract, pullulan, chitosan, and citric acid were successfully produced via Forcespinning® technology. The addition of Aloe vera extract at different weight percent loadings was investigated. The morphology, thermal properties, physical properties, and water absorption of the nanofibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The developed nanofiber membranes exhibited good water absorption capabilities, synergistic antibacterial activity against Escherichia coli, and promoted cell attachment and growth. Its porous and high surface area structure make it a potential candidate for wound dressing …