Engineering Commons^™

Soil Behavior Under Blast Loading, Jichong An

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Understanding the behavior of soil under blast loading is very important to engineers in mining, tunneling, and military construction. Due to the very complex structure of a soil mass it is very difficult to describe its constitutive relation, especially when it has different water contents and it is under blast loading conditions. New protective system designs subjected to blast loading need to be proved its validation prior to predict effect of explosive before implementation. Full-scale, buried explosive tests are costly. Finite element simulations play a significant role in the design of protective systems, for example a bottom platform of lightweight …

Progressive Failure Simulation Of Security Cable Barriers, Christopher Y. Tuan, Ratul D. Sarmah, Alexander Y. Tuan, Ching-Sheng Kao, Q. S. Li

Civil Engineering Faculty Publications

Perimeter security cable barriers are widely used by various agencies all over the world to defeat threat vehicle penetration. New barrier designs require crash test validation prior to implementation. Full-scale vehicular crash tests are costly, whereas designs via finite element simulations are time consuming and require specialized skills. Based on full-scale crash tests, an innovative and simple algorithm has been developed to model the progressive failure of security cable barriers. A multi-body approach based on the first principles of physics was developed to substantially reduce computer runtime. The solution algorithm uses a large number of small time steps. Nonlinear vehicle …

Energy Modeling Of Wireless Sensor Nodes Based On Petri Nets, Ali Shareef, Yifeng Zhu

Graduate Student Scholarly and Creative Submissions

Energy minimization is of great importance in wireless sensor networks in extending the battery lifetime. Accurately understanding the energy consumption characteristics of each sensor node is a critical step for the design of energy saving strategies. This paper develops a detailed probabilistic model based on Petri nets to evaluate the energy consumption of a wireless sensor node. The model factors critical components of a sensor node, including processors with emerging energy-saving features, wireless communication components, and an open or closed workload generator. Experimental results show that this model is more flexible and accurate than Markov models. The model provides a …

Customer Management Analysis Of Irish Plumbing & Heating Distribution System: A Simulation Study, Amr Arisha, Amr Mahfouz, John Crowe, Finbarr Bennett

Conference papers

The sudden burst of the property bubble, coupled with current global economic conditions has resulted in a huge decrease in demand for plumbing and heating fixtures in the Irish construction industry. Moreover, inefficient supply chain management policies have imposed further pressures on companies resulting in more system bottlenecks and unnecessary costs. Inventory management is seen as a functional area that can ease such bottlenecks and in turn increase supply chain efficiency, decrease costs and increase customer satisfaction. The challenge is to predict the balance of on-hand inventory and order quantity to optimise customer satisfaction and minimise inventory cost. It is …

Improving Analytical Travel Time Estimation For Transportation Planning Models, Chenxi Lu

FIU Electronic Theses and Dissertations

This dissertation aimed to improve travel time estimation for the purpose of transportation planning by developing a travel time estimation method that incorporates the effects of signal timing plans, which were difficult to consider in planning models. For this purpose, an analytical model has been developed. The model parameters were calibrated based on data from CORSIM microscopic simulation, with signal timing plans optimized using the TRANSYT-7F software. Independent variables in the model are link length, free-flow speed, and traffic volumes from the competing turning movements. The developed model has three advantages compared to traditional link-based or node-based models. First, the …

Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syngas Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

A tubular solid oxide fuel cell (SOFC) stack was modelled and its operation on biomass syn-gas was investigated. The objective of this work was to develop a computer simulation model of a biomass gasification-SOFC (BG-SOFC) system capable of predicting performance under various operating conditions and using diverse fuels. The stack was modelled using Aspen Plus and considers ohmic, activation and concentration losses. It was validated against published data for operation on natural gas. Operating parameters such as fuel and air utilisation factor U_f and U_a, current density j and steam to carbon ratio STCR were varied and …

Validation Of A Simulation Model For A Combined Otto And Stirling Cycle Power Plant, Jim Mcgovern, Barry Cullen, Michel Feidt, Stoian Petrescu

Conference Papers

A project has been underway at the Technological University Dublin (DIT) to investigate the feasibility of a combined Otto and Stirling cycle power plant in which a Stirling cycle engine would serve as a bottoming cycle for a stationary Otto cycle engine. This type of combined cycle plant is considered to have good potential for industrial use. This paper describes work by DIT and collaborators to validate a computer simulation model of the combined cycle plant. In investigating the feasibility of the type of combined cycle that is proposed there are a range of practical realities to be faced and …

Optimality Principles For Model-Based Prediction Of Human Gait, Marko Ackermann, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Although humans have a large repertoire of potential movements, gait patterns tend to be stereotypical and appear to be selected according to optimality principles such as minimal energy. When applied to dynamic musculoskeletal models such optimality principles might be used to predict how a patient's gait adapts to mechanical interventions such as prosthetic devices or surgery. In this paper we study the effects of different performance criteria on predicted gait patterns using a 2D musculoskeletal model. The associated optimal control problem for a family of different cost functions was solved utilizing the direct collocation method. It was found that fatigue-like …

Integrating Perception And Problem Solving To Predict Complex Object Behaviors, Damian M. Lyons, Sirhan Chaudhry, Marius Agica, John Vincent Monaco

Faculty Publications

One of the objectives of Cognitive Robotics is to construct robot systems that can be directed to achieve realworld goals by high-level directions rather than complex, low-level robot programming. Such a system must have the ability to represent, problem-solve and learn about its environment as well as communicate with other agents. In previous work, we have proposed ADAPT, a Cognitive Architecture that views perception as top-down and goaloriented and part of the problem solving process.

Our approach is linked to a SOAR-based problem-solving and learning framework. In this paper, we present an architecture for the perceptive and world modelling components …

Simulation Of Traffic Loading On Highway Bridges, Bernard Enright

Other resources

This work is based on weigh-in-motion measurements for approximately three million trucks obtained from sites in five European countries. Techniques have been developed, supported by photographic evidence, for filtering the measurements to identify and remove unreliable values, and for the classification of extremely heavy vehicles. The collected measurements have been used as the basis for building and calibrating a Monte Carlo simulation model for bridge loading. Two-lane traffic is simulated – either two lanes in the same direction or one lane in each direction. The model allows for vehicles that are both heavier and have more axles than in the …

Nato Human View Architecture And Human Networks, Holly A. H. Handley, Nancy P. Houston

Engineering Management & Systems Engineering Faculty Publications

The NATO Human View is a system architectural viewpoint that focuses on the human as part of a system. Its purpose is to capture the human requirements and to inform on how the human impacts the system design. The viewpoint contains seven static models that include different aspects of the human element, such as roles, tasks, constraints, training and metrics. It also includes a Human Dynamics component to perform simulations of the human system under design. One of the static models, termed Human Networks, focuses on the human-to-human communication patterns that occur as a result of ad hoc or deliberate …

Design And Validation Of A General Purpose Robotic Testing System For Musculoskeletal Applications, Lawrence D. Noble, Robb W. Colbrunn, Dong-Gil Lee, Antonie J. Van Den Bogert, Brian L. Davis

Mechanical Engineering Faculty Publications

Orthopaedic research on in vitro forces applied to bones, tendons, and ligaments during joint loading has been difficult to perform because of limitations with existing robotic simulators in applying full-physiological loading to the joint under investigation in real time. The objectives of the current work are as follows: (1) describe the design of a musculoskeletal simulator developed to support in vitro testing of cadaveric joint systems, (2) provide component and system-level validation results, and (3) demonstrate the simulator’s usefulness for specific applications of the foot-ankle complex and knee. The musculoskeletal simulator allows researchers to simulate a variety of loading conditions …

Rfid-Enabled Inventory Control Optimization: A Proof Of Concept In A Small-To-Medium Retailer, H. Dane, Katina Michael, S. F. Wamba

Faculty of Informatics - Papers (Archive)

This study examines the impact of radio-frequency identification (RFID) technology on the inventory control practices of a small-to-medium retailer using a proof of concept (PoC) approach. The exploratory study was conducted using a single case study of a hardware retailer stocking 5000 product lines provided by 110 active suppliers. To analyze the present mode of operation, procedural documents, semi-structured interviews and a participant observation was conducted. The basis for the proof of concept was a future mode of operation using a quasi-experimental design. Results indicate that in a small-to-medium retail environment, RFID technology could act as a loss prevention mechanism, …

Practical Simulation Application: Evaluation Of Process Control Parameters In Twisted-Pair Cables Manufacturing System, Amr Mahfouz, Said Hassan, Amr Arisha

Articles

Intensive competition and rapid technology development of Twisted-Pair Cables (TPC) industry have left no room for competing manufacturers to harbour system inefficiencies. TPC are used in various communication and networks hardware applications; their manufacturing facilities face many challenges including various product configurations with different equipment settings, different product flows and Work in Process (WIP) space limitations. The quest for internal efficiency and external effectiveness forces companies to align their internal settings and resources with external requirements/orders, or in different words, significant factors must be set appropriately and identified prior to manufacturing processes. Integrated definition models (IDEF0, IDEF3) in conjunction with …

Site Specific Modelling Of Traffic Loading On Highway Bridges, Bernard Enright, Eugene J. Obrien

Conference papers

Accurate traffic loading models based on measured weigh-in-motion (WIM) data are essential for the accurate assessment of existing bridges. Much work has been published on the Monte Carlo simulation of single lanes of heavy vehicle traffic, and this can easily be extended to model the loading on bridges with two streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic, such as groups of very heavy vehicles travelling together and heavy vehicles being overtaken by lighter ones. These traffic patterns affect …

The Influence Of Correlation On The Extreme Traffic Loading Of Bridges, Eugene J. Obrien, Bernard Enright, A. T. Dempsey

Conference papers

Accurate traffic loading models based on measured data are essential for the accurate assessment of existing bridges. There are well-established methods for the Monte Carlo simulation of single lanes of traffic, and this can easily be extended to model the loading on bridges with two independent streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic. This paper analyses traffic patterns using multi-lane WIM data collected at two European sites. It describes an approach to the Monte Carlo simulation of this …

Simulation Of Low Dose Positron Emission Mammography Scanner For Global Breast Health Applications, W. J Ryder, I. N Wienberg, P. S Stepanov, A Reznik, M Urdaneta, E Anashkin, M. A Masoomi, Anatoly B. Rosenfeld

Faculty of Engineering - Papers (Archive)

Positron emission mammography ("PEM") is a breast imaging modality that typically involves the administration of relatively high doses of radiotracer. In order to reduce tracer costs and consider PEM for global screening applications, it would be helpful to reduce the required amount of administered radiotracer so that patient dose would be comparable to conventional x-ray mammograms. We performed GATE Monte Carlo investigations of several possible camera configurations. Increasing the detector thickness from 10 to 30 mm, increasing the camera surface area from 5 x 20cm2 to 20 x 20cm2, and applying depth-ofinteraction information to increase the acceptance angle, increased the …

Simulation Of Macroscopic Deformation Using A Sub-Particle Dem Approach, Leela Kempton, David J. Pinson, Sheng Chew, Paul Zulli, Aibing Yu

Faculty of Engineering and Information Sciences - Papers: Part A

A limitation in numerical modelling of the ironmaking blast furnace is the lack of ability to quantify the effects of particle deformation and subsequent loss of porosity arising from the softening and melting of ferrous materials. Previous attempts to consider deformation focussed solely on the macroscopic effects such as resistance to gas flow, with an assumed decrease in porosity proportional to temperature. Instead, it is proposed to approximate particle scale deformation using a modified subparticle Discrete Element Method approach, where each 'ore' particle is represented using an agglomerate of discrete elements with temperature dependent properties. Cohesive forces binding the agglomerate …

Transferring Advanced Physics Research Tools To Education: How To Teach Simulation Tools Used In Radiation Physics Research To University Students, Susanna Guatelli, Catherine Anne Layton, Dean L. Cutajar, Anatoly B. Rosenfeld

Faculty of Engineering - Papers (Archive)

At the Centre of Medical Radiation Physics (CMRP), School of Engineering Physics, Faculty of Engineering, at the University of Wollongong (UOW), we are implementing a hands-on computing laboratory, commencing in autumn 2010, to teach scientific computing methods and modern, advanced research tools for radiation physics to postgraduate and undergraduate students. Engaging undergraduates and postgraduates together in work with a tool widely used in research laboratories is a unique development, and represents the articulation of the University’s commitment to the enhancement of the teaching/research nexus, and to the development of learning communities. The object of the laboratory is to teach students …

Design And Simulation Of Roadway Development Operations To Improve Productivity, Soumya Raghavendra Rao, Christopher D. Cook, Ernest Y. Baafi, R Porteous

Faculty of Engineering - Papers (Archive)

A typical Australian 3–5 Mt/year longwall requires 9 to 15 km of roadway to be developed every year (G. Lewis and G. Gibson: Proc. 13th Austr. Tunnelling Conf., Melbourne, Australia, May 2008, ATS, 317–326.). One of the major challenges faced by the Australian longwall mining industry is that roadway development has been unable to keep pace with improvements in longwall extraction rates. This has affected the profitability, viability and future of underground coal mines (M. Kelly: 'Coordination of roadway development strategy', ACARP report no. C5013, ACARP, Brisbane, Australia, 1997.). Gibson (G. Gibson: 'Australian roadway development– current practices', ACARP report no. …

Discrete Element Simulation Validation: Impact Plate Transfer Station, Andrew Grima, Peter W. Wypych

Faculty of Engineering - Papers (Archive)

The design of conveyor transfer stations can be a complex process to ensure that reliable flow of bulk material will occur with minimal impact on infrastructure and the environment. Classical analytical methods can be used to provide a quantitative description of the flow of bulk solids through a transfer point in regards to trajectory and velocity distribution. Discrete Element Method (DEM) is a popular alternative numerical technique for modelling and visualising gross discontinuous material flow behaviour by analysing individual particle trajectories and interactions. The Discrete Element Method methodology has been well established but there is a lack of detailed validation …

Correlation Of Nanoindentation-Induced Deformation Microstructures In Diamondlike Carbon Coatings On Silicon Substrates With Simulation Studies, Ayesha J. Haq, Paul G. Munroe, Mark Hoffman, Phil J. Martin, Avi Bendavid

Faculty of Engineering - Papers (Archive)

The effect of the presence of diamondlike carbon coatings deposited on (100) Si substrateson the deformation mechanisms operating in the silicon substrate during contact loadinghave been investigated by both cross-sectional transmission electron microscopy andmodeling of the stresses generated beneath the indenter tip. The observed subsurfacemicrostructures were correlated to the Tresca shear stress and the hydrostatic stressgenerated in the silicon substrate beneath the indenter tip. The presence of the coatingaltered the stresses generated in the substrate, and changed the deformation mechanismfrom one of principally phase transformation in uncoated Si to predominantly dislocationmotion in the silicon substrate for the diamondlike C¿Si system. …

Importance Of The Tail In Truck Weight Modeling For Bridge Assessment, Eugene J. Obrien, Bernard Enright, Abraham Getachew

Articles

To predict characteristic extreme traffic load effects, simulations are sometimes performed of bridge loading events. To generalize the truck weight data, statistical distributions are fitted to histograms of weight measurements. This paper is based on extensive WIM measurements from two European sites and shows the sensitivity of the characteristic traffic load effects to the fitting process. A semi-parametric fitting procedure is proposed: direct use of the measured histogram where there are sufficient data for this to be reliable and parametric fitting to a statistical distribution in the tail region where there are less data. Calculated characteristic load effects are shown …