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Articles 31 - 60 of 546

Full-Text Articles in Engineering

Development And Verification Of Flight Data Informed Performance Estimation And Prediction Simulation Tool For Small Electrical Multi-Rotor Uav, Nicholas Scott Borelle Jan 2022

Development And Verification Of Flight Data Informed Performance Estimation And Prediction Simulation Tool For Small Electrical Multi-Rotor Uav, Nicholas Scott Borelle

Graduate Theses, Dissertations, and Problem Reports

While small scale multi-rotor aircraft are becoming an increasingly large market with applications emerging every day, their ability to have both a high endurance/long range and a high speed/performance flight is severely limited. This leads to uncertainty in mission planning and aircraft design, specifically when deciding mission length and available on-board energy. Uncertainty like this leads to an increased chance of failure to complete the mission, and a failure to recover the aircraft. Considering that these aircraft are used by everyone from hobbyists to commercial companies to military personnel, the applications and missions being flown carry importance and a serious …


Performance Of Sensor Fusion For Vehicular Applications, Nikola Janevski Jan 2022

Performance Of Sensor Fusion For Vehicular Applications, Nikola Janevski

Graduate Theses, Dissertations, and Problem Reports

Sensor fusion is a key system in Advanced Driver Assistance Systems, ADAS. The perfor-
mance of the sensor fusion depends on many factors such as the sensors used, the kinematic
model used in the Extended Kalman Filter, EKF, the motion of the vehicles, the type of
road, the density of vehicles, and the gating methods. The interactions between parameters
and the extent to which individual parameters contribute to the overall accuracy of a sensor
fusion system can be difficult to assess.
In this study, a full-factorial experimental evaluation of a sensor fusion system based
on a real vehicle was performed. …


Predicting Pair Success In A Pair Programming Eye Tracking Experiment Using Cross-Recurrence Quantification Analysis, Maureen M. Villamor, Maria Mercedes T. Rodrigo Jan 2022

Predicting Pair Success In A Pair Programming Eye Tracking Experiment Using Cross-Recurrence Quantification Analysis, Maureen M. Villamor, Maria Mercedes T. Rodrigo

Department of Information Systems & Computer Science Faculty Publications

Pair programming is a model of collaborative learning. It has become a well-known pedagogical practice in teaching introductory programming courses because of its potential benefits to students. This study aims to investigate pair patterns in the context of pair program tracing and debugging to determine what characterizes collaboration and how these patterns relate to success, where success is measured in terms of performance task scores. This research used eye-tracking methodologies and techniques such as cross-recurrence quantification analysis. The potential indicators for pair success were used to create a model for predicting pair success. Findings suggest that it is possible to …


Noise And Time Pressure Effects On Situation Awareness And Aviation Maintenance Tasks, Syaza R. M. Haris Dec 2021

Noise And Time Pressure Effects On Situation Awareness And Aviation Maintenance Tasks, Syaza R. M. Haris

Doctoral Dissertations and Master's Theses

Aircraft maintenance technicians (AMTs) working in a line maintenance work setting are very susceptible to the deafening occupational noise from the airport vicinity or the maintenance machinery itself. Compared to a base maintenance working period, a line maintenance job requires AMTs to complete a task within a short time frame. The current study's objective is to determine if different noise levels and time pressure influence AMTs' performance and situation awareness (SA). Sixteen Embry-Riddle Aeronautical University students majoring in Aviation Maintenance Science participated in a within-subject experimental design. Each participant's performance, SA level, and perceived workload were measured during maintenance tasks …


Feasibility Analysis Of Smart Home Devices - A Domestic Consumer Perspective, A Vittaleswar Dec 2021

Feasibility Analysis Of Smart Home Devices - A Domestic Consumer Perspective, A Vittaleswar

Manipal Journal of Science and Technology

The internet of things (IoT) is a relatively new technology that establishes a global network of machines and devices capable of communicating and exchanging data over the internet. However, IoT and the internet are not the same things. IoT generates, analyzes, and makes decisions about connected objects; in other words, the IoT is smarter than the internet. One of the most common applications that make use of the IoT infrastructure to connect multiple sensors is the smart home. The sensors can detect and collect information from the environment, which is then used to control various home systems such as lighting …


Lean Application: An Assessment Of 5s On Employee Attitudes And Productivity, Nickolaos Dimitrios Karvounis Dec 2021

Lean Application: An Assessment Of 5s On Employee Attitudes And Productivity, Nickolaos Dimitrios Karvounis

STEMPS Theses & Dissertations

This study examines the effect of the implementation of 5S on employee attitudes and productivity in an Asian based facility of a global manufacturing company. Utilizing an assessment of the 5S implementation in various areas of the facility and organizational performance data for each of those areas, a non-experimental, causal comparative approach is used to analyze the impact. The study concluded that statistically significant improvements from the implementation of 5S were found both in quality and product cost for this facility; however, the study also found statistical significance where the implementation of 5S led to a decrease in performance and …


Analysis Of Energy Utilization And Losses For Jet-Propelled Vehicles, Mohammad Abbas, David W. Riggins Nov 2021

Analysis Of Energy Utilization And Losses For Jet-Propelled Vehicles, Mohammad Abbas, David W. Riggins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The global control volume-based energy utilization balance for an aerospace vehicle is extended to allow for the analysis of jet-propelled vehicles. The methodology is first developed for analyzing the energy utilization and entropy generation characteristics of jet engines without airframe considerations. This methodology, when combined with separate energy utilization analysis for an unpowered airframe, allows for the assessment of a powered vehicle. Wake entropy generation for a powered vehicle is shown to be the summation of the wake entropy generation associated with the propulsion system (no airframe) and the unpowered airframe. The fundamental relationship between overall entropy generation and the …


Assessment Of Long-Term Performance Of Pavements Containing Warm Mix Asphalt Technologies In Louisiana, Kwadwo Ampadu Boateng Jul 2021

Assessment Of Long-Term Performance Of Pavements Containing Warm Mix Asphalt Technologies In Louisiana, Kwadwo Ampadu Boateng

LSU Master's Theses

This study focused on the assessment of long-term performance of asphalt pavements containing warm mix asphalt technologies in Louisiana. A total of five rehabilitation projects were studied in the state of Louisiana. The study consisted of engineering desk analyses of field performance indicators, indices and the initial laboratory performance indicators measured for five rehabilitation projects.

The engineering desk study consisted of a review of literature from previous WMA technology projects done in Louisiana. Additionally, data was acquired and validated from the Louisiana Pavement Management System (PMS). Pavement performance indicators (i.e., cracking (transverse, longitudinal, and fatigue cracking), roughness, rutting, and pavement …


Design And Validation Of A High-Power, High Density All Silicon Carbide Three-Level Inverter, Zhongjing Wang Jul 2021

Design And Validation Of A High-Power, High Density All Silicon Carbide Three-Level Inverter, Zhongjing Wang

Graduate Theses and Dissertations

Transportation electrification is clearly the road toward the future. Compared to internal combustion engine, the electrified vehicle has less carbon-dioxide emission, less maintenance costs and less operation costs. It also offers higher efficiency and safety margin. More importantly, it relieves human’s dependence on conventional fossil energy. In the electrification progress, the revolution of electric traction drive systems is one of the most important milestone. The traction system should keep high efficiency to avoid performance reduction. Moreover, the motor drive should be designed within limited space without sacrificing output power rating. Based on the road map from US Drive Electrical and …


Optimization Of Dynamic Simulations To Identify Movement Patterns That Simultaneously Reduce The Risk Of Injury And Enhance Human Performance, Dhruv Gupta May 2021

Optimization Of Dynamic Simulations To Identify Movement Patterns That Simultaneously Reduce The Risk Of Injury And Enhance Human Performance, Dhruv Gupta

Doctoral Dissertations

Every movement, whether routine or sporting, achieves certain goals. Routine movements like walking takes us from one place to the other and sporting movements like hitting a volleyball help win the game. But each motion puts strain on certain joints of the body putting them at risk of injury. Walking can lead to chronic disorders like knee osteoarthritis over the years. Hitting a volleyball can put the shoulder at risk of a rotator cuff injury. The purpose of this work is to find optimal movement patterns that enhance human ability to achieve the goals of the movement, but at the …


New Generation Of Performance-Engineered Asphalt Mixtures Based On Balanced Mix Design Concept, Victor Manuel Garcia May 2021

New Generation Of Performance-Engineered Asphalt Mixtures Based On Balanced Mix Design Concept, Victor Manuel Garcia

Open Access Theses & Dissertations

Asphalt mixtures must ideally exhibit long-lasting durability and stability to perform wellin the field. However, improving the stability and durability of asphalt mixtures has become a major concern. Given that available design approaches rely mainly on stringent volumetric criteria for asphalt mixtures, design approaches and specifications that incorporate performance tests are needed to follow a performance-engineered mix design (PEMD) process, especially with the introduction of the balanced mix design (BMD) concept

This Dissertation study presents a comprehensive investigation of a feasible designapproach that can be implemented to develop PEMD specifications and produce BMD mixtures. An experimental evaluation of different mix …


An Investigation Into Cognitive Radio System Performance, Courtney Hardy, Lucas F. Feather, William S. Guy May 2021

An Investigation Into Cognitive Radio System Performance, Courtney Hardy, Lucas F. Feather, William S. Guy

Honors Theses

The objective of this thesis is to explore cognitive radio performance through an in-depth literature review and an implementation of a software-defined radio prototyping system. Specifically, this thesis investigates the spectrum-sensing aspect of cognitive radio by comparing two spectrum-sensing methods. It was found in the literature review that a system utilizing matched filter detection would provide higher probability of detection in low signal-to-noise ratio environments when compared to a system utilizing energy detection. These spectrum sensing methods were thus implemented and compared in the cognitive radio systems presented in this thesis. Additionally, experiments were conducted to determine the most efficient …


Quantifying The Impact Of Uncertainty In Embedded Systems Mapping For Noc Based Architectures, Wenkai Guan, Milad Ghorbani Moghaddam, Cristinel Ababei Feb 2021

Quantifying The Impact Of Uncertainty In Embedded Systems Mapping For Noc Based Architectures, Wenkai Guan, Milad Ghorbani Moghaddam, Cristinel Ababei

Electrical and Computer Engineering Faculty Research and Publications

We describe a modeling framework to capture and account for uncertainty in design parameters in embedded systems. We then develop an uncertainty-aware solution to the problem of mapping in embedded systems that uses Network-on-Chip (NoC) based architecture platforms. The problem of mapping is formulated as a multi-objective - reliability, performance, and energy consumption - optimization problem. To solve this problem, we propose a solution based on the NSGA-II genetic algorithm and Monte Carlo simulation techniques. The solution is implemented as a computer-aid design tool that can generate robust 3D Pareto frontiers in the solution space formed by the design objectives …


Effect Of Membrane Properties On The Carbonation Of Anion Exchange Membrane Fuel Cells, Yiwei Zheng, Lyzmarie Nicole Irizarry, Noor Ui Hassan, Eric R. Williams, Morgan Stefik, Jacob M. Lamanna, Daniel S. Hussey, Mustain E William Jan 2021

Effect Of Membrane Properties On The Carbonation Of Anion Exchange Membrane Fuel Cells, Yiwei Zheng, Lyzmarie Nicole Irizarry, Noor Ui Hassan, Eric R. Williams, Morgan Stefik, Jacob M. Lamanna, Daniel S. Hussey, Mustain E William

Faculty Publications

Anion exchange membrane fuel cells (AEMFC) are potentially very low-cost replacements for proton exchange membrane fuel cells. However, AEMFCs suffer from one very serious drawback: significant performance loss when CO2 is present in the reacting oxidant gas (e.g., air) due to carbonation. Although the chemical mechanisms for how carbonation leads to voltage loss in operating AEMFCs are known, the way those mechanisms are affected by the properties of the anion exchange membrane (AEM) has not been elucidated. Therefore, this work studies AEMFC carbonation using numerous high-functioning AEMs from the literature and it was found that the ionic conductivity of the …


Event-Driven Servers Using Asynchronous, Non-Blocking Network I/O: Performance Evaluation Of Kqueue And Epoll, Lorcan Leonard Jan 2021

Event-Driven Servers Using Asynchronous, Non-Blocking Network I/O: Performance Evaluation Of Kqueue And Epoll, Lorcan Leonard

Dissertations

This research project evaluates the performance of kqueue and epoll in the context of event-driven servers. The evaluation is done through benchmarking and tracing which are used to measure throughput and execution time respectively. The experiment is repeated for both a virtualised and native server environment. The results from the experiment are statistically analysed and compared. These results show significant differences between kqueue and epoll, and a profound impact of virtualisation as a variable.


Escalado De La Producción De Galactooligosacáridos A Reactor Discontinuo De 3 Y 20 Litros Usando B-Galactosidasa Kluyveromyces Lactis Libre, Karolain Cortes Santamaría, María Fernanda Gómez Pineda Jan 2021

Escalado De La Producción De Galactooligosacáridos A Reactor Discontinuo De 3 Y 20 Litros Usando B-Galactosidasa Kluyveromyces Lactis Libre, Karolain Cortes Santamaría, María Fernanda Gómez Pineda

Ingeniería de Alimentos

Los galactooligosacáridos (GOS) son compuestos empleados en alimentos funcionales por su actividad prebiótica. Se obtienen por la hidrólisis de la lactosa, empleando enzimas como β- Galactosidasa. El objetivo de este proyecto fue evaluar el efecto de escalado en la producción de GOS usando β- Galactosidasa de Kluyveromyces lactis, para ello, se empleó el lactosuero descremado y desmineralizado de la industria quesera, con el fin de obtener la lactosa que es el componente de interés para ser empleado en la producción de GOS. La lactosa fue concentrada a 33% por medio de evaporador, sin embargo, los resultados de rendimiento no fueron …


Moisture Monitoring Of A Clt Structure In A Southern Climate, Elizabeth Poblete Dec 2020

Moisture Monitoring Of A Clt Structure In A Southern Climate, Elizabeth Poblete

Graduate Theses and Dissertations

Understanding of moisture behavior in cross laminated timber (CLT) is critical to the widespread use of CLT in construction in the United States. Currently, very little data exists on the long-term impact of moisture on CLT. The objective of this research is to collect data regarding the long-term moisture variation in the CLT panel at the University of Arkansas Adohi Hall residence hall. The climate of Northwest Arkansas is different from previously monitored buildings, as they were in the Pacific Northwest. Comparatively, Northwest Arkansas has a warmer climate with higher average annual precipitation. Waterproofing efforts are usually employed to prevent …


Phonetic Algorithm Performance, Aaron Schneidereit Dec 2020

Phonetic Algorithm Performance, Aaron Schneidereit

Senior Honors Projects

AARON SCHNEIDEREIT (Computer Science BS) Phonetic Algorithm Performance Sponsors: Noah Daniels (Computer Science and Statistics) Phonetic Algorithms are used for classifying words based on their pronunciation. These algorithms are used in many text-to-speech technologies and spell-checkers to ensure that a word can be correctly recognized despite minor spelling/pronunciation errors. The process of encoding a word to its phonetic surname is known as Phonetic Matching. Since 1918, there have only been a handful of phonetic algorithms that have been created. The main three algorithms that other phonetic algorithms are built from are Soundex, New York State Identification and Intelligence System (NYSIIS), …


Phonetic Algorithm Performance, Aaron Schneidereit Dec 2020

Phonetic Algorithm Performance, Aaron Schneidereit

Senior Honors Projects

AARON SCHNEIDEREIT (Computer Science BS) Phonetic Algorithm Performance Sponsors: Noah Daniels (Computer Science and Statistics) Phonetic Algorithms are used for classifying words based on their pronunciation. These algorithms are used in many text-to-speech technologies and spell-checkers to ensure that a word can be correctly recognized despite minor spelling/pronunciation errors. The process of encoding a word to its phonetic surname is known as Phonetic Matching. Since 1918, there have only been a handful of phonetic algorithms that have been created. The main three algorithms that other phonetic algorithms are built from are Soundex, New York State Identification and Intelligence System (NYSIIS), …


On Correctness, Precision, And Performance In Quantitative Verification: Qcomp 2020 Competition Report, Carlos E. Budde, Arnd Hartmanns, Michaela Klauck, Jan Křetínský, David Parker, Tim Quatmann, Andrea Turrini, Zhen Zhang Oct 2020

On Correctness, Precision, And Performance In Quantitative Verification: Qcomp 2020 Competition Report, Carlos E. Budde, Arnd Hartmanns, Michaela Klauck, Jan Křetínský, David Parker, Tim Quatmann, Andrea Turrini, Zhen Zhang

Electrical and Computer Engineering Faculty Publications

Quantitative verification tools compute probabilities, expected rewards, or steady-state values for formal models of stochastic and timed systems. Exact results often cannot be obtained efficiently, so most tools use floating-point arithmetic in iterative algorithms that approximate the quantity of interest. Correctness is thus defined by the desired precision and determines performance. In this paper, we report on the experimental evaluation of these trade-offs performed in QComp 2020: the second friendly competition of tools for the analysis of quantitative formal models. We survey the precision guarantees - ranging from exact rational results to statistical confidence statements - offered by the nine …


Architectural Body: Performance As Design Methodology Facilitating Transformative Learning, Takako Hasegawa Oct 2020

Architectural Body: Performance As Design Methodology Facilitating Transformative Learning, Takako Hasegawa

Architecture and Planning Journal (APJ)

This paper will discuss multidisciplinary and experimental pedagogical case studies that place the importance of the body firmly back into architectural education. The advanced digital technologies currently employed almost universally in architectural education generate increasingly virtual and augmented design, resulting from processes that tend to be devoid of imagination of the body. The case studies discussed in this paper involved students’ direct participation in performative acts during the design process, facilitating positive transformative learning through direct experience. These include design briefs for Chelsea College of Arts (London, UK, 2009–2013), modules for the Architectural Association School of Architecture (AA) (London, UK, …


Hydrostatic Performance Of Reinforced Concrete Pipe For Infiltration, Lui Sammy Wong Sep 2020

Hydrostatic Performance Of Reinforced Concrete Pipe For Infiltration, Lui Sammy Wong

Electronic Thesis and Dissertation Repository

Groundwater infiltration into underground sewer systems has long been a costly issue for municipalities. With reinforced concrete pipe (RCP) being a primary option for sewer systems, existing hydrostatic testing methods conducted by manufacturers to measure internal pipe pressure, as required by specifications, do not reflect in-situ external hydrostatic conditions. This thesis records the development of a novel testing method to evaluate the RCP joint performance for infiltration. The test is safe and easy to conduct by RCP producers at the factory. The test method mimics field conditions of possible RCP joint gap and joint offset. Over 100 tests were conducted, …


Aligning Performance Management Systems For Lasting Outcomes In Humanitarian Operations, Kalyn M. Howard Sep 2020

Aligning Performance Management Systems For Lasting Outcomes In Humanitarian Operations, Kalyn M. Howard

Theses and Dissertations

Logistics is dynamic, expansive, and critical to organizational success. While it is generally believed that effective logistics management is associated with positive performance outcomes, the links between organizational practice and performance are understudied. This dissertation leverages resource-based theory and organizational learning theory to examine organizational practice and performance in non-traditional logistics settings, with particular focus on military organizations and humanitarian operational settings. First, a meta-analytical study establishes generalizable associations between various operations management practices and performance outcomes. Then, this is applied to dynamic humanitarian logistics settings, exploring how practitioners perceive practice and performance, and how this is reported and documented …


Static Characteristics Of Thermal Humidity Converters Of Liquid Materials In Continuous Flow, N.I. Avezova, P.R. Ismatullaev, Paraxat Matyakubova Aug 2020

Static Characteristics Of Thermal Humidity Converters Of Liquid Materials In Continuous Flow, N.I. Avezova, P.R. Ismatullaev, Paraxat Matyakubova

Chemical Technology, Control and Management

Thermal systems with distributed heat sources based on a pipeline segment with radial holes are proposed for the development of designs of thermal humidity converters for liquid materials. Across the liquid flow there are tubular arguments with cylindrical heat-sensitive elements, on the surface of which the heating element winding was wound, which significantly increased their sensitivity, speed, reliability and allowed the use of standard semiconductor heat-sensitive elements.


Performance Improvement Plan In Building Processaccording To Quality Leaders And Quality Improvement Tools And Techniques, Khaled El-Daghar Mar 2020

Performance Improvement Plan In Building Processaccording To Quality Leaders And Quality Improvement Tools And Techniques, Khaled El-Daghar

Architecture and Planning Journal (APJ)

The purpose of the study is to apply quality improvement tools and techniques to find out the root causes of performance problems in the building process. Performance refers to the way people do their jobs and the results of their works, seeking to solve a performance problem frequently implement a specific intervention, such as training without fully understanding the nature of the problem, or determining whether or not the chosen intervention is likely to succeed. Performance improvement approaches using a systematic methodology to find these root causes, and then implement interventions that applies to specific performance deficits. Performance improvement indicators …


Revisiting Cost Index - The Challenge Of Calculating A Precise Figure For Brazilian Airliners, Joaquim Pedro De Albuquerque D'Orey, Guilherme Amaral Da Silveira Mar 2020

Revisiting Cost Index - The Challenge Of Calculating A Precise Figure For Brazilian Airliners, Joaquim Pedro De Albuquerque D'Orey, Guilherme Amaral Da Silveira

National Training Aircraft Symposium (NTAS)

Within numerous possibilities, Cost Index (CI) is the tool that can provide economic speeds and deliver the lowest cost for a given flight. Cost Index is a highly volatile number that shifts its optimum value in several different circumstances. Through the analysis of the Brazilian regulation, operation and infrastructure reality, this paper reviews several influencers that can interfere with the optimum CI value for a specific flight, aiming for maximum precision and economy. A structured questionnaire was submitted to pilots from four of the biggest Brazilian airliners operating under part 121. The purpose of this questionnaire was to investigate whether …


Effect Of Temperature On The Performance Of Pdc Cutters With Different Shape, Zhang Suhu, Wang Chuanliu, Dai Yongbo Feb 2020

Effect Of Temperature On The Performance Of Pdc Cutters With Different Shape, Zhang Suhu, Wang Chuanliu, Dai Yongbo

Coal Geology & Exploration

In order to explore the performance of PDC cutters at different temperatures to adapt to different brazing temperatures, and to reasonably select the shape to improve efficiency. Based on the several main parameters affecting the quality of polycrystalline diamond compacts (PDC), such as wear resistance, grinding time, stationarity and impact toughness, the performance of PDC sheets from different manufacturers and different shapes was tested. The performance of PDC before or after heating and at different temperatures was obtained. At the same time, the performance of flat sheets, micro-arcs sheets and arcs sheets was compared. The results show that with the …


A Case Study Of Wifi Sniffing Performance Evaluation, Yan Li, Johan Barthelemy, Shuai Sun, Pascal Perez, Bill Moran Jan 2020

A Case Study Of Wifi Sniffing Performance Evaluation, Yan Li, Johan Barthelemy, Shuai Sun, Pascal Perez, Bill Moran

SMART Infrastructure Facility - Papers

Mobile devices regularly broadcast WiFi probe requests in order to discover available proximal WiFi access points for connection. A probe request, sent automatically in the active scanning mode, consisting of the MAC address of the device expresses an advertisement of its presence. A real-time wireless sniffing system is able to sense WiFi packets and analyse wireless traffic. This provides an opportunity to obtain insights into the interaction between the humans carrying the mobile devices and the environment. Susceptibility to loss of the wireless data transmission is an important limitation on this idea, and this is complicated by the lack of …


Using Cost-Sensitive Learning And Feature Selection Algorithms To Improve The Performance Of Imbalanced Classification, Fang Feng, Kuan-Ching Li, Jun Shen, Qingguo Zhou, Xuhui Yang Jan 2020

Using Cost-Sensitive Learning And Feature Selection Algorithms To Improve The Performance Of Imbalanced Classification, Fang Feng, Kuan-Ching Li, Jun Shen, Qingguo Zhou, Xuhui Yang

Faculty of Engineering and Information Sciences - Papers: Part A

Imbalanced data problem is widely present in network intrusion detection, spam filtering, biomedical engineering, finance, science, being a challenge in many real-life data-intensive applications. Classifier bias occurs when traditional classification algorithms are used to deal with imbalanced data. As already known, the General Vector Machine (GVM) algorithm has good generalization ability, though it does not work well for the imbalanced classification. Additionally, the state-of-the-art Binary Ant Lion Optimizer (BALO) algorithm has high exploitability and fast convergence rate. Based on these facts, we have proposed in this paper a Cost-sensitive Feature selection General Vector Machine (CFGVM) algorithm based on GVM and …


Performance Of Ballast Influenced By Deformation And Degradation: Laboratory Testing And Numerical Modeling, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn Jan 2020

Performance Of Ballast Influenced By Deformation And Degradation: Laboratory Testing And Numerical Modeling, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents a study on the deformation and degradation responses of railway ballast using large-scale laboratory testing and computational modeling approaches. A series of large-scale triaxial tests were carried out to investigate the ballast breakage responses under cyclic train loading subjected to varying frequencies, f=10-40  Hz. The role of recycled rubber energy-absorbing mats (REAMs) on reducing ballast breakage was also examined. Laboratory test results show that the ballast experiences significant degradation (breakage) and deformation, while the inclusion of REAMs can reduce the ballast breakage up to about 35%. Numerical modeling using the coupled discrete-continuum approach [coupled discrete-element method-finite-difference method …