Mechanical Engineering Commons^™

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 …

A Scalable, Chunk-Based Slicer For Cooperative 3d Printing, Jace J. Mcpherson

Computer Science and Computer Engineering Undergraduate Honors Theses

Cooperative 3D printing is an emerging technology that aims to increase the 3D printing speed and to overcome the size limit of the printable object by having multiple mobile 3D printers (printhead-carrying mobile robots) work together on a single print job on a factory floor. It differs from traditional layer-by-layer 3D printing due to requiring multiple mobile printers to work simultaneously without interfering with each other. Therefore, a new approach for slicing a digital model and generating commands for the mobile printers is needed, which has not been discussed in literature before. We propose a chunk-by-chunk based slicer that divides …

Experimental Validation Of A Numerical Phase Change Model For Microchannel Slug Flow Boiling, Christian J. Retter, Todd A. Kingston, Justin A. Weibel, Suresh V. Garimella

The Summer Undergraduate Research Fellowship (SURF) Symposium

Thermal management of high-power electronic devices continues to be a critical challenge. Flow boiling in microchannel heat sinks has been demonstrated to be an effective method for removing high heat fluxes from these devices owing to utilization of the latent heat of the fluid and the large surface area enhancement for heat exchange. However, microchannel flow boiling technologies have yet to be broadly implemented due to a lack of experimentally validated prediction and design tools. The goal of this study is to use high-fidelity experimental data to validate a previously developed numerical phase change model, to help enable physics-based prediction …

Thermophotovoltaic Devices: Combustion Chamber Optimization And Modelling To Maximize Fuel Efficiency, Arnold Chris Toppo, Ernesto Marinero, Zhaxylyk Kudyshev

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently, 110 billion cubic meters of natural gas (primarily methane), a potent greenhouse gas, are flared off for environmental and safety reasons. This process results in enough fuel to provide the combined natural gas consumption of Germany and France. The research team developed a thermophotovoltaic device to convert thermal energy to electricity at a high efficiency using proprietary emitters and combustion system. With the current focus being fuel efficiency and the combustion process, the assembly was simulated using ANSYS Fluent modelling software and the following parameters were optimized: air/fuel ratios, flow rates, and inlet sizes. Simultaneously the heat transfer across …

Development Of Iowa Dot Combination Bridge Separation Barrier With Bicycle Railing, Chaz M. Ginger

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

The Iowa Department of Transportation typically builds separation barriers between vehicle and pedestrian/bicycle facilities when sidewalks or trails are present on vehicular bridges. Currently, Iowa DOT employs a combination bridge rail that utilizes a concrete parapet that previously had been successfully evaluated to National Cooperative Highway Research Program (NCHRP) Report 350 Test Level 4 (TL-4) criteria for these situations. While the parapet had been successfully evaluated, the combination bridge rail system as a whole had not been evaluated to any crash test standards. Iowa DOT desired that researchers at Midwest Roadside Safety Facility (MwRSF) design and test a combination bridge …

Translating Data From The Laboratory Into Simulation: A Computational Framework For Subject-Specific Finite Element Musculoskeletal Simulation, Donald R. Hume

Electronic Theses and Dissertations

Computational modeling is a powerful tool which has been used to inform decisions made by engineers, scientists, and clinicians for decades. Musculoskeletal modeling has emerged as a computational modeling technique used to understand the interaction between the body and its surroundings. There are several common approaches used for musculoskeletal modeling which take advantage of different model formulations to obtain information of interest. Unfortunately, models with different joint formulations inherit disparities in representations of ligament, muscle, and cartilage at joints of interest. These differences affect the way the joint functions and limit the insight it provides through computational analysis. Musculoskeletal models …

Connected Alerts Across Manufacturing Facilities, Jordan J. Moy

Industrial and Manufacturing Engineering

The lack of communication during a large project can result in costly delays when striving to achieve previously defined benchmarks. Often times, each part of a project will require verification from an employee of a specified area of expertise before being allowed to advance to the next stage. Finding these individuals can be extremely hard due to the large, spread out campus of manufacturing facilities as well as the numerous projects the company is concurrently working on. These floor support requests can sometimes take from an hour to even a whole work day, causing major delays in the production schedule. …

The Design, Modeling, And Optimization Of A Biomimetic Soft Robot For Fluid Pumping And Thrust Generation Using Electroactive Polymer Actuators, Zakai Jedidiah Olsen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nature is a constant source of inspiration for engineers and scientists through its simple, effective, and elegant solutions to many complex problems. Smart materials and soft robotics have been seen to be particularly well suited for developing biomimetic devices and are active fields of research. In this study, the design, modeling, and optimization of a new biomimetic soft robot is described. Preliminary work was made in the modeling of a biomimetic robot based on the locomotion and kinematics of jellyfish. Modifications were made to the governing equations for jellyfish locomotion that accounted for geometric differences between biology and the robotic …

Ring And Peg Simulation For Minimally Invasive Surgical Robot, Evan Brown

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Surgical procedures utilizing minimally invasive laparoscopic techniques have shown less complications, better cosmetic results, and less time in the hospital than conventional surgery. These advantages are partially offset by inherent difficulties of the procedures which include an inverted control scheme, instrument clashing, and loss of triangulation. Surgical robots have been designed to overcome the limitations, the Da Vinci being the most widely used. A dexterous in vivo, two-armed robot, designed to enter an insufflated abdomen with a limited insertion profile and expand to perform a variety of operations, has been created as a less expensive, versatile alternative to the Da …

Formation Of Two-Way Shape Memory Effect In Niti Alloy Using Pulsed Laser Irradiation, Saidjafarzoda Ilhom, Khomidkhodza Kholikov, Peizhen Li, Dovletgeldi Seyitliyev, Zachary Thomas, Duvall Roberts, Omer San, Haluk E. Karaca, Ali O. Er

Mechanical Engineering Faculty Publications

Shape memory alloys (SMAs) are a unique class of smart materials and they were employed in various applications in engineering, biomedical, and aerospace technologies. Here, we report an advanced, efficient, and low-cost direct imprinting method with low environmental impact to create thermally controllable surface patterns. Patterned microindents were generated on Ni₅₀Ti₅₀ (at. %) SMAs using an Nd:YAG laser with 1064 nm wavelength at 10 Hz. Laser pulses at selected fluences were focused on the NiTi surface and generated pressure pulses of up to a few GPa. Optical microscope images showed that surface patterns with tailorable sizes can …

Kinesthetic Learning Experience Simulation Using An Online Intervention To Improve Hands-On Ability, David Leach

Dissertations, Master's Theses and Master's Reports

Students enrolled in mechanical and manufacturing engineering programs employ differing levels of mechanical aptitude and practical hands-on ability. Many students lack practical experience tinkering with mechanical devices and mechanisms prior to entering their post-secondary years. Student attention spans in traditional classroom environments appear to be decreasing with the ever-increasing addiction to immediate gratification provided by electronic devices, gaming software, and social media platforms. The question is then raised whether or not modern engineering students have the ability to improve mechanical aptitude by simulating a kinesthetic or tactile learning experience through an online tutorial. This project describes the development and testing …

Simulation Of An Ethylene Flame With Turbulence, Soot And Radiation Modeling, Santu Golder

Electronic Theses and Dissertations

This thesis will investigate soot models that are available in commercial codes. We will look at the effect of turbulence models, gravity, soot models and radiation. Simulations will be compared to Coppalle and Joyeux [1]. The flame is an ethylene air diffusion flame at a Reynolds number of 5700. Simulations show the SST turbulence model, one-step soot model and Rosseland radiation model including gravity agree well with experimental data (temperature and soot). Flamelet soot modeling from Carbonell et al. [2] and flamelet radiation modeling from Doom [3] has been incorporated and compared as well.

Investigation Of Microstructure And Mechanical Properties By Direct Metal Deposition, Jingwei Zhang

Doctoral Dissertations

"Microstructure and properties of Direct Metal Deposition (DMD) parts are very crucial to meeting industrial requirements of parts quality. Prediction, and control of microstructure and mechanical properties have attracted much attention during conventional metal manufacturing process under different conditions. However, there is few investigations focused on microstructure simulation and mechanical properties control under different process parameters during DMD process. This dissertation is intended to develop a multiscale model to investigate Ti6Al4V grain structure development and explore Ti6Al4V based functionally graded material (FGM) deposit properties during DMD process. The first research topic is to investigate and develop a cellular automaton-finite element …

Material Properties Design Using Simulations And Experiments For Powder Injection Molding Of Lead Zirconate Titanate (Pzt)., Bhushan Pramod Bandiwadekar

Electronic Theses and Dissertations

Powder injection molding (PIM) process simulations can be performed to minimize the number of injection molding experiments by estimating material properties necessary for PIM simulations. In current work, lead zirconate titanate (PZT) powder-polymer binder feedstock was compounded for 45 vol. % and 52 vol. % solids loading. PIM experiments on designed micro-pillar array geometry were performed using 52 vol. % PZT. Using PIM experiments results as basis, PIM simulations were performed on designed micro-pillar array geometries to understand the effectiveness of PIM simulations with the use of estimated feedstock properties in predicting molding behavior that have micro-features. Additionally, PIM simulations …

Development Mems Acoustic Emission Sensors, Adrian Enrique Avila Gomez

USF Tampa Graduate Theses and Dissertations

The purpose of this research is to develop MEMS based acoustic emission sensors for structural health monitoring. Acoustic emission (AE) is a well-established nondestructive testing technique that is typically used to monitor for fatigue cracks in structures, leaks in pressurized systems, damages in composite materials or impacts. This technology can offer a precise evaluation of structural conditions and allow identification of imminent failures or minor failures that can be addressed by planned maintenances routines. AE causes a burst of ultrasonic energy that is measured as high frequency surface vibrations (30 kHz to 1 MHz) generated by transient elastic waves that …

Performance Analysis Of Constant Speed Local Abstacle Avoidance Controller Using A Mpc Algorithym On Granular Terrain, Nicholas Haraus

Master's Theses (2009 -)

A Model Predictive Control (MPC) LIDAR-based constant speed local obstacle avoidance algorithm has been implemented on rigid terrain and granular terrain in Chrono to examine the robustness of this control method. Provided LIDAR data as well as a target location, a vehicle can route itself around obstacles as it encounters them and arrive at an end goal via an optimal route. This research is one important step towards eventual implementation of autonomous vehicles capable of navigating on all terrains. Using Chrono, a multibody physics API, this controller has been tested on a complex multibody physics HMMWV model representing the plant …

Simulating Dynamic Failure Of Polymer-Bonded Explosives Under Periodic Excitation, Rachel Kohler, Camilo Duarte Cordon, Marisol Koslowski

The Summer Undergraduate Research Fellowship (SURF) Symposium

Accidental mishandling of explosive materials leads to thousands of injuries in the US every year. Understanding the mechanisms behind the detonation process is crucial to prevent such accidents. In polymer-bonded explosives (PBX), high-frequency mechanical excitation generates thermal energy and can lead to an increase in temperature and vapor pressure, and potentially the initiation of the detonation process. However, the mechanisms behind this energy release, such as the effects of dynamic fracture and friction, are not well understood. Experimental data is difficult to collect due to the different time scales of reactions and vibrations, so research is aided by running simulations …

An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process, Amin Abedini, Wei Li, Honghan Ye

Mechanical Engineering Faculty Publications

Operating room (OR) scheduling is important. Because of increasing demand for surgical services, hospitals must provide high quality care more efficiently with limited resources. When constructing the OR schedule, it is necessary to consider the availability of downstream resources, such as intensive care unit (ICU) and post anaesthesia care unit (PACU). The unavailability of downstream resources causes blockings between every two consecutive stages. In this paper we address the master surgical schedule (MSS) problem in order to minimize blockings between two consecutive stages. First, we present a blocking minimization (BM) model for the MSS by using integer programming, based on …

Trim Tuning Of Sps-Series Dqw Crab Cavity Prototypes, S. Verdú-Andrés, J. Skaritka, Q. Wu, A. Ratti, S. Baurac, C. H. Boulware, T. Grimm, J. Yancey, W. Clemens, E. A. Mcewen, H. Park

Physics Faculty Publications

The final steps in the manufacturing of a superconducting RF cavity involve careful tuning before the final welds to match the target frequency as fabrication tolerances may introduce some frequency deviations. The target frequency is chosen based on analysis of the shifts induced by remaining processing steps including acid etching and cool down. The baseline fabrication of a DQW crab cavity for the High Luminosity LHC (HL-LHC) envisages a first tuning before the cavity subassemblies are welded together. To produce a very accurate final result, subassemblies are trimmed to frequency in the last machining steps, using a clamped cavity assembly …

Simulation And Analysis Of A Drilling Fluid Using A Herschel-Bulkley Model, Daniel Powell

Mechanical Engineering ETDs

In the study, a drilling fluid with known properties is analyzed and simulated in the laminar regime through a pipe with dimensions of 1.5m in length and 0.02m in diameter. The purpose of the conducted analysis is to demonstrate the advantages of the Herschel-Bulkley model currently used in the oil and gas industry for analyzing non-Newtonian drilling fluids.

For comparison, the analysis is also performed using more simple models for non-Newtonian fluids such as the Bingham Plastic model and the Power Law model and for a Newtonian fluid (water). In addition to analytical models, computations are conducted using …

Venus Lander Design, Garon Morgan, Brian Rodrigues, Dhruv Sachani, Jason Scott

Capstone Design Expo Posters

The students designed an Entry, Descent, and Landing (EDL) system for a lander to reach the surface of Venus. The students used a combination of 3D modelling and programming to design the EDL within given constraints under specific tolerances. An EDL takes into consideration entry flight dynamics, aeroheating, and landing systems. The EDL was divided into three stages (see below). The separation of stages was designed to address unique challenges found at different points throughout the EDL. The primary objective of the first stage was to minimize the heat associated with the entry velocity to the payload. The second stage …

Simulation Study On Effect Of Gas Charging And Egr In A Dual-Fuel Engine, Satyavenkata Naga Sai Sharath Gorthy

Dissertations, Master's Theses and Master's Reports

Natural gas combined with diesel as micro pilot has the capabilities of achieving lower NOx and soot emissions. Optimization of the combustion process in engines with natural gas and diesel micro-pilot is essential to achieve higher efficiencies and loads. Gas charging (intake air boosting) and EGR are two technologies which when implemented in the natural gas-diesel engines, provide the opportunity to achieve higher efficiencies and loads and low emissions. Simulation study is one of the approaches to investigate the extent and effects of gas charging and EGR on the performance of the engine. With the rapid improvements over the past …

Simulation Of Human Ankle Trajectory During Stance Phase Of Gait, Leslie Castelino

Dissertations, Master's Theses and Master's Reports

A simulation was developed which mimics the human gait characteristics based on the input of an individual’s gait trajectory. This simulation also estimates the impedance of the human ankle based on the ground reaction forces measured by the force plate. This simulation will accept alterations of the following parameters: total body weight, weight of the shank, weight of the foot, trajectories of the shank and foot of the individual and orientation of the force plate, which would generate a new gait trajectory for the ankle during the stance phase of gait. The goal of this simulation was to validate the …

Formation Flight For Fuel Saving In Coronet Missions Of Kc-135r And F-15c/E, Christopher Allen Kniffin

Mechanical and Aerospace Engineering Theses - Archive

The fuel saving benefit of formation flight has been demonstrated through theoretical and computational analyses, simulation, wind tunnel and flight tests. When an aircraft flies in a specific region in the wake of another aircraft, it experiences upwash, which results in reduced drag and thus reduced thrust requirement. One specific USAF mission that can potentially benefit from formation flight is coronet missions. In a coronet mission, fighter aircraft are escorted and refueled, as needed, by tanker aircraft over a long range. During the flight, the receiver aircraft fly in formation with the tanker but outside of the wake of the …

Evaluating Alternative Scheduling Rules To Improve Scheduling Performance, Bryan Allan White

Theses and Dissertations

In this study a powder painting production line was examined for the purpose of improving on its scheduling. A simulation model was developed to compare the performance of alternative scheduling rules. The simulation model utilized scheduling data from the original system in order to determine how accurately it represented the original system. The model was built using the discrete event simulation software Arena. The validated model was used to test a set of scheduling rules that would change the sequence in which orders in the queue were processed. By looking at the different rules and the effects on the final …

Temperature Distributions Influencing Lateral Spread In Industrial Hot Rolling, Baohui Tian, Siegfried Kleber, Silvia Zinner, Peter Markiewicz

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

The Simulation For Ultrasonic Testing Based On Frequency-Phase Coded Excitation, Jiaying Zhang, Wenlong Tian, Tie Gang, Sen Cong, Zhaoyang Sheng

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Study On Growth Model Of Cellular Automata Method In Solidification Simulation, Zhao Guo, Jian-Xin Zhou, Ya-Jun Yin, Chang-Chang Liu

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Integration Of Advanced Simulation And Visualization For Material Processing, Chenn Zhou

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Optimizing The Telescope Assembly Alignment Simulator For Sofia, Zoe E. Sharp, Alex Quyenvo, Jennifer Briggs, Brian Eney

STAR Program Research Presentations

The Stratospheric Observatory for Infrared Astronomy (SOFIA) conducts research on a modified Boeing 747sp aircraft. By using a variety of infrared science instruments mounted on a 2.7 meter telescope, researchers can make discoveries about the galactic center, star formation, and various topics associated with a deeper understanding of our universe. To efficiently collect data through the SOFIA instruments, the instruments must be tested and prepared prior to being placed on the aircraft. Therefore, with the use of the Telescope Assembly Alignment Simulator (TAAS), researchers can design and construct improvements needed for these instruments to efficiently perform while in flight. The …