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Mechanical Engineering Faculty Publications

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Articles 271 - 300 of 618

Full-Text Articles in Mechanical Engineering

Prognostics Models For Railroad Tapered Roller Bearings With Spall Defects On Inner Or Outer Rings, Constantine Tarawneh, Jennifer Lima, Nancy De Los Santos, Robert Jones Jul 2019

Prognostics Models For Railroad Tapered Roller Bearings With Spall Defects On Inner Or Outer Rings, Constantine Tarawneh, Jennifer Lima, Nancy De Los Santos, Robert Jones

Mechanical Engineering Faculty Publications

Rolling contact fatigue (RCF) is one of the major causes of failure in railroad bearings used in freight service. Subsurface inclusions resulting from impurities in the steel used to fabricate the bearings initiate subsurface fatigue cracks, which propagate upwards and cause spalling of the rolling surfaces. These spalls start small and propagate as continued operation induces additional crack formation and spalling. Studies have shown that the bearing temperature is not a good indicator of spall initiation. In many instances, the temperature of the bearing increases markedly only when the spall has spread across major portions of the raceway. In contrast, …

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Multidirectional Pin-On-Disk Testing Device To Evaluate The Cross-Shear Effect On The Wear Of Biocompatible Materials, Vicente Cortes, Carlos A. Rodriguez Betancourth, Javier A. Ortega, Hasina Huq Jul 2019

Multidirectional Pin-On-Disk Testing Device To Evaluate The Cross-Shear Effect On The Wear Of Biocompatible Materials, Vicente Cortes, Carlos A. Rodriguez Betancourth, Javier A. Ortega, Hasina Huq

Mechanical Engineering Faculty Publications

One of the main causes of hip prostheses failure is the premature wear of their components. Multi-directional motion or “cross-shear” motion has been identified as one of the most significant factors affecting the wear rate of UHMWPE in total hip joint replacement prostheses. To better evaluate the effect of this cross-shear motion on the tribological behavior of different biomaterials, a new wear testing device has been designed and developed. This new instrument is capable to reproduce the “cross-shear” effect with bidirectional motion on bearing materials and to determine coefficient of friction (COF) between surfaces during testing. To validate the functionality …

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Prototyping A Conductive Polymer Steering Pad For Rail Freight Service, Anthony A. Villarreal, Constantine Tarawneh, Miguel Ontiveros, James Aranda, Robert Jones Jul 2019

Prototyping A Conductive Polymer Steering Pad For Rail Freight Service, Anthony A. Villarreal, Constantine Tarawneh, Miguel Ontiveros, James Aranda, Robert Jones

Mechanical Engineering Faculty Publications

The AdapterPlus™ steering pad is a polymer component on a railcar that helps to reduce stresses on the axle as a railcar rounds a curve. One railway application requires a minimum of 240 mA to be passed through the steering pad to the rail, which activates air valves that control automated cargo gates. Currently, two copper studs are inserted into the pad to provide a conductive path. However, after continuous cyclic loading caused by normal service operation, the copper studs deform, wear, and eventually lose contact between the two surfaces rendering the pad nonconductive. One proposed solution to this problem …

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Estimating The Outer Ring Defect Size And Remaining Service Life Of Freight Railcar Bearings Using Vibration Signatures, Joseph Montalvo, Constantine Tarawneh, Jennifer Lima, Jonas Cuanang, Nancy De Los Santos Jul 2019

Estimating The Outer Ring Defect Size And Remaining Service Life Of Freight Railcar Bearings Using Vibration Signatures, Joseph Montalvo, Constantine Tarawneh, Jennifer Lima, Jonas Cuanang, Nancy De Los Santos

Mechanical Engineering Faculty Publications

The railroad industry currently utilizes two wayside detection systems to monitor the health of freight railcar bearings in service: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). TADS™ uses wayside microphones to detect and alert the conductor of high-risk defects. Many defective bearings may never be detected by TADS™ since a high-risk defect is a spall which spans more than 90% of a bearing’s raceway, and there are less than 20 systems in operation throughout the United States and Canada. Much like the TADS™, the HBD is a device that sits on the side of the …

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Implementation Of Visual Supplements To Strengthen Pedagogical Practices And Enhance The Physical Understanding Of Fundamental Concepts In Engineering Mechanics, Eleazar Marquez, Samuel Garcia, Samuel Molina Jun 2019

Implementation Of Visual Supplements To Strengthen Pedagogical Practices And Enhance The Physical Understanding Of Fundamental Concepts In Engineering Mechanics, Eleazar Marquez, Samuel Garcia, Samuel Molina

Mechanical Engineering Faculty Publications

Mechanical Engineering is a discipline highly dependent on designing and implementing mechanical, thermal, or energy systems for the improvement of the human environment. Thus being a proficient Engineer involves having a strong mathematical background and a thorough physical understanding on how systems operate in order to apply analytical or numerical schemes during a design process. However, most of the students’ academic development is centered on deriving tedious equations and solving textbook problems, which are difficult to visualize and physically understand, and cloud their intuitive nature to comprehend a problem on its entirety. These conventional approaches and methods of disseminating content …

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Statistical Optimization Of Stress Level In Mg-Li-Al Alloys Upon Hot Compression Testing, Rezawana Islam, Meysem Haghshenas Jun 2019

Statistical Optimization Of Stress Level In Mg-Li-Al Alloys Upon Hot Compression Testing, Rezawana Islam, Meysem Haghshenas

Mechanical Engineering Faculty Publications

In the present study, a response optimization method using Extreme Vertices Mixer Design (EVMD) approach is proposed for stress optimization in a thermomechanically processed Mg-Li-Al alloy. Experimentation was planned as per mixed design proportions of Mg, Li and Al and process variables (i.e. temperature and strain rate). Each experiment has been performed under different conditions of factors proportions and process variables. The response, particularly stress has been considered for each experiment. The response is optimized to find an optimum condition when the contributing factors influence material characteristics in such a way, to achieve better strength, ductility and corrosion resistance. Estimated …

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Creating A Learning Environment That Engages Engineering Students In The Classroom Via Communication Strategies, Eleazar Marquez, Samuel Garcia Jun 2019

Creating A Learning Environment That Engages Engineering Students In The Classroom Via Communication Strategies, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this research effort, the authors claim that possessing technical knowledge is not a sufficient asset to establish a learning environment that renders engagement with engineering students during lecture sessions, but rather the integration of various communication strategies that support students’ academic development. Research has noted that classroom context and conditions impact the degree of student learning and engagement and are further enhanced when students feel comfortable communicating with the instructor and with their peers. If such acquaintance is nonexistent, student participation may be stifled and limited despite the technical concerns arising during lecture sessions. Thus, it is imperative for …

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Magnesium Nanocomposites: An Overview On Time-Dependent Plastic (Creep) Deformation, Meysem Haghshenas, Manoj Gupta Apr 2019

Magnesium Nanocomposites: An Overview On Time-Dependent Plastic (Creep) Deformation, Meysem Haghshenas, Manoj Gupta

Mechanical Engineering Faculty Publications

Magnesium (Mg) nanocomposites are created when nano-size particles are embedded into the Mg (or Mg alloy) matrix. The Mg nanocomposites, cited as high-strength energy-saving materials of future, are a group of emerging materials with excellent combination of strength and ductility and superior specific strength property (strength-to-weight ratio). Having said this, Mg nanocomposites are considered as promising replacement for other structural alloys (i.e. aluminum and titanium) wherever low density and high strength are required, i.e. transportation, aerospace, defense, etc. To be able to apply this group of materials for real components, different failure mechanisms at ambient and elevated temperatures under …

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Limit Equilibrium Method-Based Shear Strength Prediction For Corroded Reinforced Concrete Beam With Inclined Bars, Yafei Ma, Baoyong Lu, Zhongzhao Guo, Lei Wang, Hailong Chen, Jianren Zhang Mar 2019

Limit Equilibrium Method-Based Shear Strength Prediction For Corroded Reinforced Concrete Beam With Inclined Bars, Yafei Ma, Baoyong Lu, Zhongzhao Guo, Lei Wang, Hailong Chen, Jianren Zhang

Mechanical Engineering Faculty Publications

Shear strength is a widely investigated parameter for reinforced concrete structures. The corrosion of reinforcement results in shear strength reduction. Corrosion has become one of the main deterioration factors in reinforced concrete beam. This paper proposes a shear strength model for beams with inclined bars based on a limit equilibrium method. The proposed model can be applied to both corroded and uncorroded reinforced concrete beams. Besides the tensile strength of longitudinal steel bars, the shear capacity provided by the concrete on the top of the diagonal crack, the tensile force of the shear steel at the diagonal crack, the degradation …

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Linear Stability Analysis Of Subaqueous Bedforms Using Direct Numerical Simulations, ‪Nadim Zgheib, S. Balachandar Feb 2019

Linear Stability Analysis Of Subaqueous Bedforms Using Direct Numerical Simulations, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

We present results on the formation of ripples from linear stability analysis. The analysis is coupled with direct numerical simulations of turbulent open-channel flow over a fixed sinusoidal bed. The presence of the sediment bed is accounted for using the immersed boundary method. The simulations are used to extract the bed shear stress and consequently the sediment transport rate. The approach is different from traditional linear stability analysis in the sense that the phase lag between the bed topology and the sediment flux is obtained from the three-dimensional turbulent simulations. The stability analysis is performed on the Exner equation, whose …

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Forcespinning Technique For The Production Of Poly(D,L-Lactic Acid) Submicrometer Fibers: Process–Morphology–Properties Relationship, Victoria Padilla-Gainza, Graciela Morales, Heriberto Rodríguez-Tobías, Karen Lozano Feb 2019

Forcespinning Technique For The Production Of Poly(D,L-Lactic Acid) Submicrometer Fibers: Process–Morphology–Properties Relationship, Victoria Padilla-Gainza, Graciela Morales, Heriberto Rodríguez-Tobías, Karen Lozano

Mechanical Engineering Faculty Publications

This work addresses a systematic study for the process development and optimization of poly(d,l-lactic acid) (PDLLA) submicrometer fibers utilizing the centrifugal spinning technique known as Forcespinning. This study analyzes the effect of polymer concentration (8, 10, and 12 wt %) and angular speed on the fiber morphology, diameter distribution, and fiber yield. The increase in polymer concentration and angular speed favored the formation of continuous and homogeneous submicrometer fibers with an absence of bead formation and higher output. The optimal conditions were established considering the morphological characteristics that exhibit a greater surface area (homogeneous and submicrometer fibers); and they were …

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Electrical Properties And Electromagnetic Interference Shielding Effectiveness Of Interlayered Systems Composed By Carbon Nanotube Filled Carbon Nanofiber Mats And Polymer Composites, Claudia A. Ramirez-Herrera, Homero Gonzalez, Felipe De La Torre, Laura Benitez, Jose G. Cabanas-Moreno, Karen Lozano Feb 2019

Electrical Properties And Electromagnetic Interference Shielding Effectiveness Of Interlayered Systems Composed By Carbon Nanotube Filled Carbon Nanofiber Mats And Polymer Composites, Claudia A. Ramirez-Herrera, Homero Gonzalez, Felipe De La Torre, Laura Benitez, Jose G. Cabanas-Moreno, Karen Lozano

Mechanical Engineering Faculty Publications

The demand for multifunctional requirements in aerospace, military, automobile, sports, and energy applications has encouraged the investigation of new composite materials. This study focuses on the development of multiwall carbon nanotube (MWCNT) filled polypropylene composites and carbon nanofiber composite mats. The developed systems were then used to prepare interlayered composites that exhibited improved electrical conductivity and electromagnetic interference (EMI) shielding efficiency. MWCNT-carbon nanofiber composite mats were developed by centrifugally spinning mixtures of MWCNT suspended in aqueous poly(vinyl alcohol) solutions. The developed nanofibers were then dehydrated under sulfuric acid vapors and then heat treated. Interlayered samples were fabricated using a nanoreinforced …

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Design And Analysis Of Novel Actuation Mechanism With Controllable Stiffness, Erivelton Gualter Dos Santos, Hanz Richter Feb 2019

Design And Analysis Of Novel Actuation Mechanism With Controllable Stiffness, Erivelton Gualter Dos Santos, Hanz Richter

Mechanical Engineering Faculty Publications

Actuators intended for human–machine interaction systems are usually designed to be mechanically compliant. Conventional actuators are not suitable for this purpose due to typically high stiffness. Advanced powered prosthetic and orthotic devices can vary their stiffness during a motion cycle and are power-efficient. This paper proposes a novel actuator design that modulates stiffness by means of a flexible beam. A motorized drive system varies the active length of the cantilever beam, thus achieving stiffness modulation. New large deflection formulation for cantilever beams with rolling contact constraints is used to determine the moment produced by the actuator. To validate the proposed …

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Achieving Superelasticity In Additively Manufactured Niti In Compression Without Post-Process Heat Treatment, Narges Shayesteh Moghaddam, Soheil Saedi, Amirhesam Amerinatanzi, Alejandro Hinojos, Ali Ramazani, Julia Kundin, Michael J. Mills, Haluk E. Karaca, Mohammad Elahinia Jan 2019

Achieving Superelasticity In Additively Manufactured Niti In Compression Without Post-Process Heat Treatment, Narges Shayesteh Moghaddam, Soheil Saedi, Amirhesam Amerinatanzi, Alejandro Hinojos, Ali Ramazani, Julia Kundin, Michael J. Mills, Haluk E. Karaca, Mohammad Elahinia

Mechanical Engineering Faculty Publications

Shape memory alloys (SMAs), such as Nitinol (i.e., NiTi), are of great importance in biomedical and engineering applications due to their unique superelasticity and shape memory properties. In recent years, additive manufacturing (AM) processes have been used to produce complex NiTi components, which provide the ability to tailor microstructure and thus the critical properties of the alloys, such as the superelastic behavior and transformation temperatures (TTs), by selection of processing parameters. In biomedical applications, superelasticity in implants play a critical role since it gives the implants bone-like behavior. In this study, a methodology of improving superelasticity in Ni-rich NiTi components …

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Fabrication And Characterization Of Centrifugally Spun Poly(Acrylic Acid) Nanofibers, David De La Garza, Francisco De Santiago, Luis Materon, Mircea Chipara, Mataz Alcoutlabi Jan 2019

Fabrication And Characterization Of Centrifugally Spun Poly(Acrylic Acid) Nanofibers, David De La Garza, Francisco De Santiago, Luis Materon, Mircea Chipara, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

The production of poly(acrylic acid) (PAA) nanofibers by the centrifugal spinning of PAA solutions in water is reported. The effect of the spinneret rotational speed and concentration of PAA solutions on the diameter of nanofibers and on their quality (assessed by the absence of beads) is discussed. The main physical properties of PAA such as glass-transition temperature (Tg) are studied in detail and compared to the feature of the as-received homopolymer. It is shown that the glass-transition temperature of the bulk PAA and PAA nanofibers (as measured by differential scanning calorimetry) depends on the heating rate according …

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Computationally Efficient, Multi-Domain Hybrid Modeling Of Surface Integrity In Machining And Related Thermomechanical Finishing Processes, Julius M. Schoop, David Adeniji, Ian S. Brown Jan 2019

Computationally Efficient, Multi-Domain Hybrid Modeling Of Surface Integrity In Machining And Related Thermomechanical Finishing Processes, Julius M. Schoop, David Adeniji, Ian S. Brown

Mechanical Engineering Faculty Publications

In order to enable more widespread implementation of sophisticated process modeling, a novel, rapidly deployable multi-physics hybrid model of surface integrity in finishing operations is proposed. Rather than modeling detailed chip formation mechanics, as is common in numerical models, the proposed models integrates existing analytical and semi-empirical models of the plastic, elastic, thermal and thermodynamic domains. Using this approach, highly complex surface integrity phenomena such as residual stresses, grain size, phase composition, microhardness profile, etc. can be accurately predicted in a manner of seconds. It is envisioned that this highly efficient modeling scheme will drive new innovations in surface engineering.

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Metabolic Cost Calculations Of Gait Using Musculoskeletal Energy Models, A Comparison Study, Anne D. Koelewijn, Dieter Heinrich, Antonie J. Van Den Bogert Jan 2019

Metabolic Cost Calculations Of Gait Using Musculoskeletal Energy Models, A Comparison Study, Anne D. Koelewijn, Dieter Heinrich, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

This paper compares predictions of metabolic energy expenditure in gait using seven metabolic energy expenditure models to assess their correlation with experimental data. Ground reaction forces, marker data, and pulmonary gas exchange data were recorded for six walking trials at combinations of two speeds, 0.8 m/s and 1.3 m/s, and three inclines, -8% (downhill), level, and 8% (uphill). The metabolic cost, calculated with the metabolic energy models was compared to the metabolic cost from the pulmonary gas exchange rates. A repeated measures correlation showed that all models correlated well with experimental data, with correlations of at least 0.9. The model …

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Human Gait Analysis Metric For Gait Retraining, Tyagi Ramakrishnan, Seok Hun Kim, Kyle B. Reed Jan 2019

Human Gait Analysis Metric For Gait Retraining, Tyagi Ramakrishnan, Seok Hun Kim, Kyle B. Reed

Mechanical Engineering Faculty Publications

The combined gait asymmetry metric (CGAM) provides a method to synthesize human gait motion. The metric is weighted to balance each parameter’s effect by normalizing the data so all parameters are more equally weighted. It is designed to combine spatial, temporal, kinematic, and kinetic gait parameter asymmetries. It can also combine subsets of the different gait parameters to provide a more thorough analysis. The single number quantifying gait could assist robotic rehabilitation methods to optimize the resulting gait patterns. CGAM will help define quantitative thresholds for achievable balanced overall gait asymmetry. The study presented here compares the combined gait parameters …

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The Educational Value Of Modelling Complex Thermodynamic Systems With System Dynamics Software, Stephen Crown, Constantine Tarawneh Jan 2019

The Educational Value Of Modelling Complex Thermodynamic Systems With System Dynamics Software, Stephen Crown, Constantine Tarawneh

Mechanical Engineering Faculty Publications

The solution of problems involving complex thermodynamic systems often occupies much of a students' time and can be a distraction from them developing a clear understanding of system components, interaction of subsystems, modelling simplifications and assumptions, and design optimization. Refocusing students on the fundamental concepts of thermal systems design and analysis is possible with the introduction of system modelling software that carries some of the load of repetitive calculation required for complex systems. Models of thermodynamic systems encountered in an advanced undergraduate thermodynamics course were developed by students (some provided to students) to solve homework problems of complex steam power …

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Simulation Of Droplet Impacting A Square Solid Obstacle In Microchannel With Different Wettability By Using High Density Ratio Pseudopotential Multiplerelaxation- Time (Mrt) Lattice Boltzmann Method (Lbm), Wandong Zhao, Ying Zhang, Wenqiang Shang, Zhaotai Wang, Ben Xu, Shuisheng Jiang Jan 2019

Simulation Of Droplet Impacting A Square Solid Obstacle In Microchannel With Different Wettability By Using High Density Ratio Pseudopotential Multiplerelaxation- Time (Mrt) Lattice Boltzmann Method (Lbm), Wandong Zhao, Ying Zhang, Wenqiang Shang, Zhaotai Wang, Ben Xu, Shuisheng Jiang

Mechanical Engineering Faculty Publications

In this paper, a pseudopotential high density ratio (DR) lattice Boltzmann Model was developed by incorporating multi-relaxation-time (MRT) collision matrix, large DR external force term, surface tension adjustment external force term and solid-liquid pseudopotential force. It was found that the improved model can precisely capture the two-phase interface at high DR. Besides, the effects of initial Reynolds number, Weber number, solid wall contact angle (CA), ratio of obstacle size to droplet diameter ( 1 χ ), ratio of channel width to droplet diameter ( 2 χ ) on the deformation and breakup of droplet when impacting on a square obstacle …

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Sediment Patterns From Fluid-Bed Interactions: A Direct Numerical Simulations Study On Fluvial Turbulent Flows, ‪Nadim Zgheib, S. Balachandar Jan 2019

Sediment Patterns From Fluid-Bed Interactions: A Direct Numerical Simulations Study On Fluvial Turbulent Flows, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

We present results on the initial formation of ripples from an initially flattened erodible bed. We use direct numerical simulations (DNS) of turbulent open channel flow over a fixed sinusoidal bed coupled with hydrodynamic stability analysis. We use the direct forcing immersed boundary method to account for the presence of the sediment bed. The resolved flow provides the bed shear stress and consequently the sediment transport rate, which is needed in the stability analysis of the Exner equation. The approach is different from traditional linear stability analysis in the sense that the phase lag between the bed topology, and the …

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Nurturing Brilliance In Engineering: Creating Research Venues For Undergraduate Underrepresented Minorites In Engineering As An Initiative From Faculty Members That Foster Academic Inclusion, Development, And Postgraduation Instruction, Eleazar Marquez, Samuel Garcia Jan 2019

Nurturing Brilliance In Engineering: Creating Research Venues For Undergraduate Underrepresented Minorites In Engineering As An Initiative From Faculty Members That Foster Academic Inclusion, Development, And Postgraduation Instruction, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this study, a new model for attracting, advancing, and advocating for the participation of underrepresented minorities in research venues is proposed with the intention of fostering academic inclusion, development, and post-graduation mentorship. It involves developing and nurturing a disposition from faculty by proactively identifying students via classroom interaction, performance, and academic aptitude and extending a personal invitation to collaborate on the research team. Current research opportunities for engineering undergraduates at tier-one institutions are obtained by students' incentive to communicate with faculty members via email or office hours. Despite the available opportunities, only a limited number of students are selected …

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Performance Of C2H4 Reductant In Activated-Carbon-Supported Mnox-Based Scr Catalyst At Low Temperatures, Guangli Liu, Dongtai Han, Jie Cheng, Yongshi Feng, Wenbin Quan, Li Yang, Kozo Saito Dec 2018

Performance Of C2H4 Reductant In Activated-Carbon-Supported Mnox-Based Scr Catalyst At Low Temperatures, Guangli Liu, Dongtai Han, Jie Cheng, Yongshi Feng, Wenbin Quan, Li Yang, Kozo Saito

Mechanical Engineering Faculty Publications

Hydrocarbons as reductants show promising results for replacing NH3 in SCR technology. Therefore, considerable interest exists for developing low-temperature (< 200 °C) and environmentally friendly HC-SCR catalysts. Hence, C2H4 was examined as a reductant using activated-carbon-supported MnOx-based catalyst in low-temperature SCR operation. Its sensitivity to Mn concentration and operating temperature was parametrically studied, the results of which showed that the catalyst activity followed the order of 130 °C > 150 °C > 180 °C with an optimized Mn concentration near 3.0 wt.%. However, rapid deactivation of catalytic activity also occurred when using C2H4 as the reductant. The mechanism of deactivation was explored and is …

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Coordinated Unmanned Aircraft System (Uas) And Ground-Based Weather Measurements To Predict Lagrangian Coherent Structures (Lcss), Peter J. Nolan, James Pinto, Javier González-Rocha, Anders Jensen, Christina N. Vezzi, Sean C. C. Bailey, Gijs De Boer, Constantin Diehl, Roger Laurence Iii, Craig W. Powers, Hosein Foroutan, Shane D. Ross, David G. Schmale Iii Dec 2018

Coordinated Unmanned Aircraft System (Uas) And Ground-Based Weather Measurements To Predict Lagrangian Coherent Structures (Lcss), Peter J. Nolan, James Pinto, Javier González-Rocha, Anders Jensen, Christina N. Vezzi, Sean C. C. Bailey, Gijs De Boer, Constantin Diehl, Roger Laurence Iii, Craig W. Powers, Hosein Foroutan, Shane D. Ross, David G. Schmale Iii

Mechanical Engineering Faculty Publications

Concentrations of airborne chemical and biological agents from a hazardous release are not spread uniformly. Instead, there are regions of higher concentration, in part due to local atmospheric flow conditions which can attract agents. We equipped a ground station and two rotary-wing unmanned aircraft systems (UASs) with ultrasonic anemometers. Flights reported here were conducted 10 to 15 m above ground level (AGL) at the Leach Airfield in the San Luis Valley, Colorado as part of the Lower Atmospheric Process Studies at Elevation—a Remotely-Piloted Aircraft Team Experiment (LAPSE-RATE) campaign in 2018. The ultrasonic anemometers were used to collect simultaneous measurements of …

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Opensim Versus Human Body Model: A Comparison Study For The Lower Limbs During Gait, Antoine Falisse, Sam Van Rossom, Johannes Gijsbers, Frans Steenbrink, Ben J. Van Basten, Ilse Jonkers, Antonie J. Van Den Bogert, Friedl De Groote Dec 2018

Opensim Versus Human Body Model: A Comparison Study For The Lower Limbs During Gait, Antoine Falisse, Sam Van Rossom, Johannes Gijsbers, Frans Steenbrink, Ben J. Van Basten, Ilse Jonkers, Antonie J. Van Den Bogert, Friedl De Groote

Mechanical Engineering Faculty Publications

Musculoskeletal modeling and simulations have become popular tools for analyzing human movements. However, end users are often not aware of underlying modeling and computational assumptions. This study investigates how these assumptions affect biomechanical gait analysis outcomes performed with Human Body Model and the OpenSim gait2392 model. The authors compared joint kinematics, kinetics, and muscle forces resulting from processing data from 7 healthy adults with both models. Although outcome variables had similar patterns, there were statistically significant differences in joint kinematics (maximal difference: 9.8 degrees {[}1.5 degrees] in sagittal plane hip rotation), kinetics (maximal difference: 0.36 {[}0.10] N.m/kg in sagittal plane …

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Use Of The Wilshire Equations To Correlate And Extrapolate Creep Data Of Inconel 617 And Nimonic 105, Vito Cedro Iii, Christian Garcia, Mark Render Dec 2018

Use Of The Wilshire Equations To Correlate And Extrapolate Creep Data Of Inconel 617 And Nimonic 105, Vito Cedro Iii, Christian Garcia, Mark Render

Mechanical Engineering Faculty Publications

Advanced power plant alloys must endure high temperatures and pressures for durations at which creep data are often not available, necessitating the extrapolation of creep life. A recently developed creep life extrapolation method is the Wilshire equations, with which multiple approaches can be used to increase the goodness of fit of available experimental data and improve the confidence level of calculating long-term creep strength at times well beyond the available experimental data. In this article, the Wilshire equation is used to extrapolate the creep life of Inconel 617 and Nimonic 105 to 100,000 h. The use of (a) different methods …

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Cfd Modeling On Hydrodynamic Characteristics Of Multiphase Counter-Current Flow In A Structured Packed Bed For Post-Combustion Co2 Capture, Li Yang, Fang Liu, Kozo Saito, Kunlei Liu Nov 2018

Cfd Modeling On Hydrodynamic Characteristics Of Multiphase Counter-Current Flow In A Structured Packed Bed For Post-Combustion Co2 Capture, Li Yang, Fang Liu, Kozo Saito, Kunlei Liu

Mechanical Engineering Faculty Publications

Solvent-based post combustion CO2 capture is a promising technology for industrial application. Gas-liquid interfaces and interactions in the packed bed are considered one of the key factors affecting the overall CO2 absorption rate. Understanding the hydrodynamic characterizations within packed beds is essential to identify the appropriate enhanced mass transfer technique. However, multiphase counter-current flows in the structured packing typically used in these processes are complicated to visualize and optimize experimentally. In this paper, we aim to develop a comprehensive 3D multiphase, counter-current flow model to study the liquid/gas behavior on the surface of structured packing. The output from …

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A Parametric Study Of Wave Interaction With A Rotor Having Hydrofoil Blades, Yingchen Yang, Fredrick A. Jenet, Ben Xu, Juan Carlos Garza, Benjamin Tamayo, Yessica Chavez, Oscar Reyes, Samuel Fuentes Oct 2018

A Parametric Study Of Wave Interaction With A Rotor Having Hydrofoil Blades, Yingchen Yang, Fredrick A. Jenet, Ben Xu, Juan Carlos Garza, Benjamin Tamayo, Yessica Chavez, Oscar Reyes, Samuel Fuentes

Mechanical Engineering Faculty Publications

Our recent progress on studying wave interaction with a lift-type rotor is discussed in this paper. The particular focus is on characterization of the rotor’s unidirectional responsiveness in waves. The rotor consists of six hydrofoil blades in two sets. One blade set has three blades laid out as a vertical-axis wind turbine of the Darrieus type. The other blade set has three blades configured like a Wells turbine. In combination, the formed rotor can be driven by flows in any direction to perform unidirectional rotation about its vertically mounted shaft. This unidirectional responsiveness of the rotor also holds in waves, …

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Capturing The Competing Influence Of Thermal And Mechanical Loads On The Strain Of Turbine Blade Coatings Via High Energy X-Rays, Albert Manero, Kevin Knipe, Janine Wischek, Carla Meid, John Okasinski, Jonathan Almer, Anette M. Karlsson, Marion Bartsch, Seetha Raghavan Sep 2018

Capturing The Competing Influence Of Thermal And Mechanical Loads On The Strain Of Turbine Blade Coatings Via High Energy X-Rays, Albert Manero, Kevin Knipe, Janine Wischek, Carla Meid, John Okasinski, Jonathan Almer, Anette M. Karlsson, Marion Bartsch, Seetha Raghavan

Mechanical Engineering Faculty Publications

This paper presents findings of synchrotron diffraction measurements on tubular specimens with a thermal barrier coating (TBC) system applied by electron beam physical vapor deposition (EB-PVD), having a thermally grown oxide (TGO) layer due to aging in hot air. The diffraction measurements were in situ while applying a thermal cycle with high temperature holds at 1000 °C and varying internal air cooling mass flow and mechanical load. It was observed that, during high temperature holds at 1000 °C, the TGO strain approached zero if no mechanical load or internal cooling was applied. When applying a mechanical load, the TGO in-plane …

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Use Of The Wilshire Equations To Correlate And Extrapolate Creep Data Of Hr6w And Sanicro 25, Vito Cedro Iii, Christian Garcia, Mark Render Sep 2018

Use Of The Wilshire Equations To Correlate And Extrapolate Creep Data Of Hr6w And Sanicro 25, Vito Cedro Iii, Christian Garcia, Mark Render

Mechanical Engineering Faculty Publications

Advanced power plant alloys must endure high temperatures and pressures for durations at which creep data are often not available, necessitating the extrapolation of creep life. Many methods have been proposed to extrapolate creep life, and one of recent significance is a set of equations known as the Wilshire equations. With this method, multiple approaches can be used to determine creep activation energy, increase the goodness of fit of available experimental data, and improve the confidence level of calculating long-term creep strength at times well beyond the available experimental data. In this article, the Wilshire equation is used to extrapolate …

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