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Numerical Simulation Of Fully Grouted Rock Bolts, Hossein Jalalifar, Naj Aziz

Faculty of Engineering - Papers (Archive)

This chapter describes the application of numerical modelling to civil and mining projects, particularly rock bolting, developing a Final Element (FE) model for the bolt, grout, rock, and two interfaces under axial and lateral loading, verifying the model, analysing the stress and strains developed in the bolt and surrounding materials. Numerical methods are the most versatile computational methods for various engineering disciplines because a structure is discritised into small elements and the constitutive equations that describe the individual elements and their interactions are constructed. Finally, these numerous equations are solved together simultaneously using computers. The results from this procedure include …

Simulation Of Water And Contaminant Transport Through Vadose Zone - Redistribution System, Thidarat Bunsri, Muttucumaru Sivakumar, Dharmappa Hagare

Faculty of Engineering - Papers (Archive)

Movement of water in vadose zone, mainly focusing on infiltration and percolation that involves percolation of water under gravity from soil surface and redistribution which is the capillary rise of water movement upwards, is presented. In the global hydrologic cycle, 76% of the precipitating water enters the soil via percolation-infiltration, which leads to the downward movement of water (L’vovich 1974). The water used by natural processes, can move downwards due to infiltration and lift from groundwater table during natural redistribution process. The forecasting of water movement in unsaturated infiltration redistribution system is linked between soil hydraulic properties and hydrologic condition …

Role Of Vanguard Counter-Potential In Terahertz Emission Due To Surface Currents Explicated By Three-Dimensional Ensemble Monte Carlo Simulation, David Cortie, Roger A. Lewis

Faculty of Engineering - Papers (Archive)

The discovery that short pulses of near-infrared radiation striking a semiconductor may lead to emission of radiation at terahertz frequencies paved the way for terahertz time-domain spectroscopy. Previous modeling has allowed the physical mechanisms to be understood in general terms but it has not fully explored the role of key physical parameters of the emitter material nor has it fully revealed the competing nature of the surface-field and photo-Dember effects. In this context, our purpose has been to more fully explicate the mechanisms of terahertz emission from transient currents at semiconductor surfaces and to determine the criteria for efficient emission. …

Introduction To The Geant4 Simulation Toolkit, Susanna Guatelli, D Cutajar, Bradley Oborn, Anatoly B. Rosenfeld

Faculty of Engineering - Papers (Archive)

Geant4 is a Monte Carlo simulation Toolkit, describing the interactions of particles with matter. Geant4 is widely used in radiation physics research, from High Energy Physics, to medical physics and space science, thanks to its sophisticated physics component, coupled with advanced functionality in geometry description. Geant4 is widely used at the Centre for Medical Radiation Physics (CMRP), at the University of Wollongong, to characterise and optimise novel detector concepts, radiotherapy treatments, and imaging solutions. This lecture consists of an introduction to Monte Carlo method, and to Geant4. Particular attention will be devoted to the Geant4 physics component, and to the …

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. …

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. …

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 …

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 …

Dem Simulation Of Effect Of Confining Pressure On Ballast Behaviour, P K. Thakur, Buddhima Indraratna, Jayan Sylaja J S Vinod

Faculty of Engineering - Papers (Archive)

In this paper, an attempt has been made to investigate the influence of confining pressure on deformation and degradation behaviourof railway ballast using the Discrete Element Method (DEM). A novel approach has been employed to model the two dimensionalprojection of field size ballast particles as cluster of bonded particles. Bonded particles are held together by a bond, and debonding isconsidered as particle breakage. A series of cyclic loading simulations using DEM were carried out on an assembly of angular ballast particles at different confining pressures (10 kPa to 240 kPa). The results highlight that the development of axial strain during …

Simulation Of Impulsive Loading On Column Using Inflatable Airbag Technique, Alexander Remennikov, J Y Richard Liew, Kong Sih Ying, K W. Kang

Faculty of Engineering - Papers (Archive)

The purpose of this study was to simulate impulsive loading on columns by an innovative lab-based experimental technique that utilises inflatable airbags. Mild and stainless steel hollow sectioin columns with effective lengths of 955mm and under simply supported condition were used in this study.

Simulation Of Water Movement Through Unsaturated Infiltration-Redistribution System, Thidarat Bunsri, Muttucumaru Sivakumar, Dharmappa Hagare

Faculty of Engineering - Papers (Archive)

This paper deals with the movement of water in a natural unsaturated zone, focusing on infiltration-redistribution system. Infiltration refers to the downward movement of water due to the gravitational force and redistribution defines the upward movement of water due to the capillary rise. Under natural conditions, the movement of water through an infiltration-redistribution depended upon the relations among water content, hydraulic conductivity and tension of soil pore. Various combinations of water balance concepts, Richards' equation, soil-physics theory and capillary height concepts were applied to mathematically model the movement of water through infiltration-redistribution system. The accuracy and computational efficiency of the …

Molecular Dynamics Simulation Of Crack Propagation On Different Slip Planes Of Bcc Iron, Y. Gao, C. Lu, A. K. Tieu, H. T. Zhu

Faculty of Engineering - Papers (Archive)

In this paper, molecular dynamic simulations of crack propagation in body centre cubic (bcc) single crystal have been performed. The crack propagation behaviors on two different slip planes ({1 1 0} and {2 1 1}) have been investigated. A self-adaptive time step algorithm has been proposed to increase the stability of the simulations. It has been found that the slip plane significantly affects the propagation speed of the crack.

Validated Computer Simulation Modelling For Complete Conveyor Transfer Design, David B. Hastie, Andrew P. Grima, Peter W. Wypych

Faculty of Engineering - Papers (Archive)

This paper presents the chute flow analysis for a granular cohesionless material in a hood and spoon style transfer chute and bench scale testing methods to calculate the coefficient of restitution, particle rotation restraint and the coefficient of friction between particles of granular material. The experimental chute flow investigations were performed on a conveyor transfer research facility located at the University of Wollongong, using high-speed video to capture the granular flow and subsequently analysed with the Image Pro Plus software package. The bench scale tests were analysed to determine the input parameters for the DEM simulations of the trajectories and …

Simulation Of The Reinforced Concrete Slabs Under Impact Loading, Faham Tahmasebinia, Alexander Remennikov

Faculty of Engineering - Papers (Archive)

Many older structures were designed for static loads but more recently there has been a growing awareness that some must be designed to resist both dynamic impact and static loads. An accidental impact load can be caused by mishaps in industry as well as accidents stemming from transportation or man-made disasters. There are number of ways of predicting how an impact load will affect a concrete slab, some of which may be impractical or expensive but because there have been significant developments in technology, numerical techniques rather than experimental approaches have become popular methods for developing detailed responses Therefore, to …

Finite Element Simulation Of Mandrel Penetration In A Normally Consolidated Soil, Cholachat Rujikiatkamjorn, Ali Ghandeharioon, Buddhima Indraratna

Faculty of Engineering - Papers (Archive)

In this paper, a finite element simulation of the mandrel penetration in normally consolidated soils is presented using a commercial finite element code (ABAQUS). A coupled analysis with large-strain frictional contact is used to simulate the soil-mandrel interface during mandrel penetration. The modified Cam clay model is used to represent the soft soil. The numerical predictions are then compared with the results obtained from the large scale laboratory tests to predict the extent of the smear zone. A large scale consolidation test was conducted with the rate-controlled device used to install the mandrel. The associated excess pore pressures at various …

Simulation Of Dynamic Recrystallization Using Irregular Cellular Automata, N Yazdipour, A Dehghan-Manshadi, C H. J Davies, P D. Hodgson

Faculty of Engineering - Papers (Archive)

Computer simulation is a powerful tool to predict microstructure and its evolution during dynamic recrystallization. Cellular Automata (CA), as one of the most efficient methods proposed to simulate recrystallization and grain growth. In this work, recrystallization and grain growth phenomena were modelled by using a two dimensional irregular CA method. Initial grain size, nuclei density and orientation of each grain were variables which have been used as entering data to the CA model. Final grain size, orientation of each grain, dislocation density and stress-strain curve were the results which have been resulted to validate the current model. Considering the model …

Simulation Study Of Quadrupole Dielectrophoretic Trapping, Weihua Li, J Sun, B Liu, X Z. Zhang

Faculty of Engineering - Papers (Archive)

This paper presents a numerical study of particle trapping using quadrupole microfludic dielectrophoretic device. By taking into account the dielectrophoreis, viscous drag, the trajectory of particles flowing through the quadrupole device was obtained. Simulation results show that the device is effective for negative trapping, where particles are effectively trapped at the device centre. The device geometry is optimized by maximizing the dielectrophoretic force.

Fault Diagnosis In Multi-Station Assembly Systems Using An Agent-Based Simulation Model, Nagesh Shukla, Manoj Tiwari, Darek Ceglarek

Faculty of Engineering - Papers (Archive)

Today’s automotive industries require quick ramp-up in order to shorten the time to market and fulfill greater demand for product variety. Since, dimensional tolerance problems are one of the main causes for delay during ramp-up in multi-station assembly systems; hence, rapid diagnosis of faults contributing to dimensional errors is of significant concern. This paper presents an agent-based simulation model (ABSM) which integrates model-based and data-based diagnostics for fault diagnosis and correction in multi-station assembly processes. The fault causing variation sources, their effects on dimensional accuracy, diagnosis from sensors data and corrective actions in multi-station assembly systems are simulated using proposed …

Numerical Simulation Of Pile Group Behaviour In Liquefying Sloping Ground, Deepa S. Liyanapathirana

Faculty of Engineering - Papers (Archive)

This paper investigates pile group behaviour in liquefying sloping ground. The numerical procedure utilised involves two main steps. First a ground response analysis is carried out using a stress path model to obtain the maximum ground displacements along the pile and the degraded soil modulus over the depth of the soil deposit. Next a dynamic analysis is carried out for a single pile in the group assuming that each pile in the group behaves in the same way during the earthquake loading. The method has been verified using centrifuge data, where soil liquefaction has been observed in laterally spreading sloping …

The Simulation Of Magnetorheological Elastomers Adaptive Tuned Dynamic Vibration Absorber For Automobile Engine Vibration Control, X.C Zhang, X.Z. Zhang, W.H. Li, B. Liu, X.L. Gong, P.Q Zhang

Faculty of Engineering - Papers (Archive)

The aim of this article is to investigate the use of a Dynamic Vibration Absorber to control vibration of engine by using simulation. Traditional means of vibration control have involved the use of passive and more recently, active methods. This study is different in that it involves an adaptive component in the design of vibration absorber using magnetorheological elastomers (MREs) as the adaptive spring.

MREs are kind of novel smart material whose shear modulus can be controlled by applied magnetic field. In this paper, the vibration mode of a simple model of automobile engine is simulated by Finite Element Method …

Impact Resistance Of Reinforced Concrete Columns: Experimental Studies And Design Considerations, Alexander Remennikov, Sakdirat Kaewunruen

Faculty of Engineering - Papers (Archive)

There are instances where reinforced concrete structures designed for static loads are subjected to accidental or deliberate impact or blast loads because of industrial or transportation accidents, military or terrorist activities. Analysis and design of structures for such events require realistic assessment of the ulti-mate impact resistance and a mode of failure of the structure. In this paper, a series of falling weight impact tests on conventionally designed reinforced concrete columns are described. The behaviour of quarter-scale reinforced concrete columns under static and impact loads is presented. An impact load was applied at the mid-height of the columns by a …

Simulation Of Travelling Wave Dielectrophoresis Using A Meshless Method, Dafeng Chen, Hejun Du, Weihua Li, Chang Shu

Faculty of Engineering - Papers (Archive)

Manipulation and separation of micron-sized particles, particularly biological particles, using the dielectrophoretic effect is an emerging application in BioMEMS technology. This paper presents a numerical simulation for the four-phase traveling dielectrophoresis (DEP) using a novel meshless method - weighted least square finite difference (LSFD) scheme. The exact boundary condition and nonuniform point distribution were used in the calculation. Numerical results including the electrical potential, electrical field, traveling wave DEP forces and particle behavior are presented. Although the LSFD scheme was originally proposed in solving incompressible viscous flow, it is further demonstrated in this paper that the method is also well …

Cellular Neural Network Based Deformation Simulation With Haptic Force Feedback, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith

Faculty of Engineering - Papers (Archive)

This paper presents a new methodology for deformable object modelling by drawing an analogy between cellular neural network (CNN) and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by the non-linear CNN activity. An improved CNN model is developed for propagating the energy generated by the external force on the object surface in the natural manner of Poisson equation. The proposed methodology models non-linear materials with nonlinear CNN rather than geometric non-linearity in the most existing deformation methods. It can not only …

Modelling And Simulation Of The Magnetically Impelled Arc Butt (Miab) Process For Transmission Pipeline Applications, John Norrish, Dominic Cuiuri, Mohammad Hossain

Faculty of Engineering - Papers (Archive)

Early patents for the Magnetically Impelled Arc Butt process (MIAB) date back to 1940 [1] and the basic principles of the process have remained unchanged from this time. The process was however refined in the 1970s for use in the production of automotive components and has been used extensively in this area. Investigation of the process for pipe girth welding have been reported and commercial pipe welding heads are reported to be available in the Ukraine [2], Although the process is well established it is believed that a more fundamental analysis of the mechanisms involved would assist in the optimisation …

Deformable Object Simulation With Poisson Equation, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith

Faculty of Engineering - Papers (Archive)

This paper presents a new methodology for the deformation of soft objects by drawing an analogy between Poisson equation and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by the Poisson equation. An improved Poisson model is developed for propagating the energy generated by the external force in a natural manner. A method is presented to derive the internal forces from the potential energy distribution. This proposed methodology not only deals with large-range deformations, but also accommodates both isotropic and anisotropic materials …

Implementation Of A New Monte Carlo Simulation Tool For The Development Of A Proton Therapy Beam Line And Verification Of The Related Dose Distributions, G A. P Cirrone, G Cuttone, S Guatelli, S Lo Nigro, B Mascialino, M G. Pia, L Raffaele, G Russo, M G. Sabini

Faculty of Engineering - Papers (Archive)

Using the Monte Carlo simulation tool GEANT4 we simulated the hadron-therapy beam line of the CATANA center. CATANA is the unique italian hadron-therapy facility in which 62 AMeV proton beams are used for the radiotherapeutic treatment of choroidal and iris melanomas. All the elements, such as diffusers, range shifters, collimators and detectors, typical of a proton-therapy line were modelled. The CATANA beam line provides an ideal environment for the experimental testing and validation of the software developed. The software architecture was developed, and now the validation of the software is in its final stage. Simulated ranges, energy distribution, depth and …

Geometric Modelling Of The Temporal Bone For Cochlea Implant Simulation, Catherine Todd, Fazel Naghdy, S. J. O'Leary

Faculty of Engineering - Papers (Archive)

The first stage in the development of a clinically valid surgical simulator for training otologic surgeons in performing cochlea implantation is presented. For this purpose, a geometric model of the temporal bone has been derived from a cadaver specimen using the biomedical image processing software package Analyze (AnalyzeDirect, Inc) and its three-dimensional reconstruction is examined. Simulator construction begins with registration and processing of a Computer Tomography (CT) medical image sequence. Important anatomical structures of the middle and inner ear are identified and segmented from each scan in a semi-automated threshold-based approach. Linear interpolation between image slices produces a three-dimensional volume …

Simulation Of The Effect Of Wind On Rectangular Sedimentation Tanks, Muttucumaru Sivakumar, S A. Lowe

Faculty of Engineering - Papers (Archive)

A numerical model is presented to simulate the effect of wind action on rectangular sedimentation tanks used in water and wastewater treatment plants. The mathematical model uses the k-r. model for fl uid flow and sediment transport, and is solved using an explicit finite diffence scheme incorporating a penalty function approach. Simulations of fluid flow velocity and aeqiment concentration are presented for two wind speeds in two directions. It is shown that the effect of wind action is significant and future design of sedimentation tanks should include this parameter.