Social and Behavioral Sciences Commons^™

Computational Simulation Of Eccentrically Loaded Circular Thin-Walled Concrete-Filled Double Steel Tubular Slender Columns, Mizan Ahmed, Qing Liang, Vipulkumar Patel, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

The concrete confinement provided by the circular steel tubes improves the performance of circular concretefilled double steel tubular (CFDST) columns, which have increasingly been employed as high-performance structural members in tall buildings. This paper presents computational and design models for the simulation and design of high strength CFDST slender columns composed of circular thin-walled sections that are eccentrically loaded. The formulation of the computational model is described, which takes into account the influences of concrete confinement, geometric imperfection, second-order, gradual plasticity of steel, and geometric and material nonlinearities. The inverse quadratic method is implemented in computational algorithms which solve the …

Chemical Clogging Of Granular Media Under Acidic Groundwater Conditions-Experimental Simulation, Buddhima Indraratna, Subhani Kanchanama Medawela, Senura Athuraliya, Ana Heitor, Pankaj Baral

Faculty of Engineering and Information Sciences - Papers: Part B

Generation of acidic groundwater attributed to pyrite oxidation in low-lying acid sulfate soil causes substantial damage to the soil-water environment and civil infrastructure. The installation of Permeable Reactive Barrier (PRB) is a frontier technology in the field of acid neutralisation and for removing toxic heavy metal cations, e.g. soluble Fe and Al. This study aims to assess the potential of limestone (calcite) aggregates as the PRB's main reactive material in low-lying pyritic land. During long-term laboratory column experiments, a significant capacity of limestone for removing the contaminant chemical species was observed. Nevertheless, the formation of secondary mineral precipitates upon geochemical …

Performance Simulation And Evaluation Of Net Zero Energy Buildings In An Australian Coastal Climate, Joel Anderson, Duane A. Robinson, Zhenjun Ma

Faculty of Engineering and Information Sciences - Papers: Part B

Net zero energy buildings (NZEB) are becoming more common, and as new energy saving designs and technologies become available, the ability to estimate overall energy use and understand the impact on operation of building appliances will become important. This paper outlines simulation results of performance improvements achieved by modifying various components (glazing, lighting, thermal comfort settings) of two tertiary education NZEBs and a typical modern commercial building. The DesignBuilder models' thermal performance and energy consumption were validated using real data from case study buildings. The work shows validating models of smaller, less conven-tional, buildings is more difficult than for larger …

Fiber Element Simulation Of Interaction Behavior Of Local And Global Buckling In Axially Loaded Rectangular Concrete-Filled Steel Tubular Slender Columns Under Fire Exposure, Ghanim Mohammed Kamil, Qing Quan Liang, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Slender rectangular thin-walled concrete-filled steel tubular (CFST) columns in composite building structures exposed to fire may experience the interaction of local and global buckling. Numerical investigations on the interaction buckling responses of such columns under fire exposure have been rarely reported. This paper describes a fiber-based computational model for the prediction of the fire-resistance and interaction responses of local and global buckling of concentrically-loaded slender CFST columns made of rectangular sections exposed to fire. The thermal analysis is undertaken to calculate the distribution of temperatures in the column cross-section considering the effects of the air gap between concrete and steel, …

Nonlinear Post-Fire Simulation Of Concentrically Loaded Rectangular Thin-Walled Concrete-Filled Steel Tubular Short Columns Accounting For Progressive Local Buckling, Ghanim Mohammed Kamil, Qing Quan Liang, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

The repair of fire-damaged thin-walled rectangular concrete-filled steel tubular (CFST) columns in engineering structures after fire exposure requires the assessment of their residual strength and stiffness. Existing numerical models have not accounted for the effects of local buckling on the post-fire behavior of CFST columns with rectangular thin-walled sections. This paper describes a nonlinear post-fire simulation technique underlying the theory of fiber analysis for determining the residual strengths and post-fire responses of concentrically loaded short thin-walled rectangular CFST columns accounting for progressive local buckling. The post-fire stress-strain laws for concrete in rectangular CFST columns are proposed based on available test …

Two Decades Of Advancement In Process Simulation Testing Of Ballast Strength, Deformation, And Degradation, Buddhima Indraratna, Ngoc Trung Ngo, Sanjay Nimbalkar, Cholachat Rujikiatkamjorn

Faculty of Engineering and Information Sciences - Papers: Part B

This paper describes salient features of a set of large-scale ballast testing equipment developed at the University of Wollongong, Australia, and how the test results and research outcomes have contributed to transforming tracks in the Australian heavy haul and commuter networks, particularly with regards to the strength, deformation, and degradation of ballast. Ideally, ballast assemblies should be tested in prototype scale under actual loading conditions. This is because a reduction in particle sizes for testing in smaller equipment can reduce the internal angle of friction (shearing resistance) of the granular assembly in a macro sense, and the angularity of the …

Editorial: Modelling And Simulation In Health Care Systems, Nagesh Shukla, Pascal Perez, Manoj K. Tiwari, Darek Ceglarek, Joana M. Dias

Faculty of Engineering and Information Sciences - Papers: Part A

Increasingly, changes in population demography, technological and medical advancements, and others, have affected the paradigm of health and social care systems worldwide. These changes have direct effect on organisation and working of health care systems whether they are hospitals, general practitioners or long-term care. An efficient and effective health care system is crucial for high quality of the life in the society. In recent times, major challenges faced by health care systems are accurate diagnosis, operational issues (such as bottlenecks, low throughput, low resource utilisation), hospital redesign, workforce planning and scheduling, streamlining of patient flow, performance management, disease monitoring, and …

Stabilization Of Track Substructure With Geoinclusions- Experimental Evidence And Dem Simulation, Ngoc Trung Ngo, Buddhima Indraratna, Cholachat Rujikiatkamjorn

Faculty of Engineering and Information Sciences - Papers: Part A

This article reviews on current knowledge of rail track geomechanics, including several important concepts and topics related to laboratory testing and computational modelling, to study the shear stress-strain and deformation of ballast improved by geosynthetics and recycled rubber mats. The effect that impact loads have on ballast degradation and its mitigation due to resilient synthetic mats (i.e. rubber mats) between the ballast and the subballast is investigated using large-scale impact-testing apparatus. Computational modelling with finite element and discrete element methods are increasingly being used to model ballasted tracks reinforced with geosynthetics to capture the continuum media of formation soils and …

Simulation Of The Melting Process Of Ice Slurry For Energy Storage Using A Two-Fluid Lattice Boltzmann Method, Qi Lin, Shugang Wang, Zhenjun Ma, Jihong Wang, Tengfei Zhang

Faculty of Engineering and Information Sciences - Papers: Part B

Ice slurry can be used as the thermal storage media in latent cool storage systems for both residential and commercial buildings. This paper presents the investigation of the phase change characteristics of the ice slurry using a two-fluid Lattice Boltzmann Method (TFLBM). The melting and migration processes of the ice slurry are simulated by improving the equilibrium distribution function and matching the relevant parameters such as the kinetic viscosity of ice particle cluster and cross-collision coefficient. The sensitivity analysis of the ice slurry viscosity and cross-collision coefficient are achieved through six numerical experiments, and the ice melting in the internal-melt …

Ventilative Cooling Through Automated Window Opening Control Systems To Address Thermal Discomfort Risk During The Summer Period: Framework, Simulation And Parametric Analysis, Theofanis Psomas, Massimo Fiorentini, Georgios Kokogiannakis, Per K. Heiselberg

Faculty of Engineering and Information Sciences - Papers: Part B

Automated window opening control systems with integrated ventilative cooling strategies may significantly diminish the thermal discomfort and overheating risk of dwellings during cooling periods in temperate climates. One of the challenges with demonstrating the benefits of the systems is the lack of building performance simulation (BPS) tools which may represent precisely how actual algorithms are applied.

The study supported herein aims to present a framework of how to simulate an advanced ventilative cooling algorithm of a window system on coupled BPS environments (ESP-r and BCVTB tools). Parametric analysis has been conducted to verify specific operational functions of the system. The …

Performance Simulation Of A Ground Source Heat Pump System Integrated With Solar Photovoltaic Thermal Collectors For Residential Application, Lei Xia, Zhenjun Ma, Georgios Kokogiannakis

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents the simulation and performance evaluation of a ground source heat pump (GSHP) system integrated with water-based solar photovoltaic thermal (PVT) collectors for residential buildings. A dynamic simulation system is developed using TRNSYS and used to facilitate the performance evaluation of the system. A 20-year life-time performance simulation is performed under three operation scenarios with different sizes of the PVT collectors. The results showed that the performance of the system is highly dependent on the size of the PVT collectors. Furthermore, an economic analysis is carried out to determine the optimum size of the PVT collectors for the …

Gvm Based Intuitive Simulation Web Application For Collision Detection, Binbin Yong, Jun Shen, Zebang Shen, Huaming Chen, Xin Wang, Qingguo Zhou

Faculty of Engineering and Information Sciences - Papers: Part B

Computer simulation, which has been proved to be an effective approach to problem solving, is nowadays widely used in modern science. However, it requires a lot of computing resources, which are difficult for general users to acquire. In this paper, we design a Web based system to implement on-line simulation system for ordinary users. As a useful example, the simulation of one type of collision detection model is presented in this paper. Moreover, the software application of simulation is offered as a service on Web. Meanwhile, the incorporation of general vector machine (GVM, a type of neural network) to intelligently …

Effect Of Deformation On Microstructure And Mechanical Properties Of Dual Phase Steel Produced Via Strip Casting Simulation, Zhiping Xiong, Andrii Kostryzhev, Nicole Stanford, Elena V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

The strip casting is a recently appeared technology with a potential to significantly reduce energy consumption in steel production, compared to hot rolling and cold rolling. However, the quantitative dependences of the steel microstructure and mechanical properties on strip casting parameters are unknown and require investigation. In the present work we studied the effects of strain and interrupted cooling temperature on microstructure and mechanical properties in conventional dual phase steel (0.08C-0.81Si-1.47Mn-0.03Al wt%). The strip casting process was simulated using a Gleeble 3500 thermo-mechanical simulator. The steel microstructures were studied using optical, scanning and transmission electron microscopy. Mechanical properties were measured …

Organ Doses From Hepatic Radioembolization With 90y, 153sm, 166ho And 177lu: A Monte Carlo Simulation Study Using Geant4, N A A Hashikin, C H Y Yeong, Susanna Guatelli, B J J Abdullah, K H. Ng, Alessandra Malaroda, Anatoly B. Rosenfeld, A C. Perkins

Faculty of Engineering and Information Sciences - Papers: Part A

90Y-radioembolization is a palliative treatment for liver cancer. 90Y decays via beta emission, making imaging difficult due to absence of gamma radiation. Since post-procedure imaging is crucial, several theranostic radionuclides have been explored as alternatives. However, exposures to gamma radiation throughout the treatment caused concern for the organs near the liver. Geant4 Monte Carlo simulation using MIRD Pamphlet 5 reference phantom was carried out. A spherical tumour with 4.3cm radius was modelled within the liver. 1.82GBq of 90Y sources were isotropically distributed within the tumour, with no extrahepatic shunting. The simulation was repeated with 153Sm, 166Ho and 177Lu. The estimated …

Microstructure And Mechanical Properties Of Strip Cast Trip Steel Subjected To Thermo-Mechanical Simulation, Zhiping Xiong, Andrii Kostryzhev, Liang Chen, Elena V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

Instead of hot rolling and cold rolling followed by annealing, strip casting is a more economic and environmentally friendly way to produce transformation-induced plasticity (TRIP) steels. According to industrial practice of strip casting, rapid cooling in this work was achieved using a dip tester, and a Gleeble 3500 thermo-mechanical simulator was used to carry out the processing route. A typical microstructure of TRIP steels, which included ~0.55 fraction of polygonal ferrite with bainite, retained austenite and martensite, was obtained. The effects of deformation (0.41 reduction) above non-recrystallisation temperature, isothermal bainite transformation temperature and the size of second phase region on …

An Implementation Of Discrete Electron Transport Models For Gold In The Geant4 Simulation Toolkit, D Sakata, Sebastien Incerti, M Bordage, N Lampe, Susumu Okada, Dimitris Emfietzoglou, Ioanna Kyriakou, K Murakami, Takashi Sasaki, H Tran, Susanna Guatelli, V Ivantchenko

Faculty of Engineering and Information Sciences - Papers: Part A

Gold nanoparticle (GNP) boosted radiation therapy can enhance the biological effectiveness of radiation treatments by increasing the quantity of direct and indirect radiation-induced cellular damage. As the physical effects of GNP boosted radiotherapy occur across energy scales that descend down to 10 eV, Monte Carlo simulations require discrete physics models down to these very low energies in order to avoid underestimating the absorbed dose and secondary particle generation. Discrete physics models for electron transportation down to 10 eV have been implemented within the Geant4-DNA low energy extension of Geant4. Such models allow the investigation of GNP effects at the nanoscale. …

Particle Size Segregation Of Bulk Material In Dustiness Testers Via Dem Simulation, Sathaphon Wangchai, David B. Hastie, Peter W. Wypych

Faculty of Engineering and Information Sciences - Papers: Part A

Dustiness testers are used to quantify the level of dust within a bulk material. The generation of dust can occur as a result of many bulk material handling activities, including filling or discharge from storage bins, during free-fall, material impact on conveyor transfers, or impact with other materials. Dust generation can have a serious impact to the environment as well as workers and nearby communities. This paper presents the findings of a discrete element modeling (DEM) study of the flow behavior of a range of binary granular mixes tested in the European Standard and the Australian Standard dustiness testers. Due …

Coupling A Thermal Comfort Model With Building Simulation For User Comfort And Energy Efficiency, Katharina Boudier, Massimo Fiorentini, Sabine Hoffmann, Raghuram Kalyanam, Georgios Kokogiannakis

Faculty of Engineering and Information Sciences - Papers: Part B

This paper describes a methodology for coupling an advanced model of the thermo-regulatory system of the human body that describes its physiological processes, a comfort model that evaluates thermal sensation and comfort, and the ESP-r building simulation software that computes the transient thermal response of a building model. The objective of this study was to utilise the physiology and comfort models to dynamically modify the heating and cooling temperature set points of a zone controller in ESP-r, in accordance with the computed human thermal sensation and achieve realtime thermal comfort management. The comunication between the software is managed by the …

The Shear Response Of Copper Bicrystals With Σ11 Symmetric And Asymmetric Tilt Grain Boundaries By Molecular Dynamics Simulation, Liang Zhang, Cheng Lu, A Kiet Tieu, Xing Zhao, Linqing Pei

Faculty of Engineering and Information Sciences - Papers: Part A

Grain boundaries (GBs) are important microstructure features and can significantly affect the properties of nanocrystalline materials. Molecular dynamics simulation was carried out in this study to investigate the shear response and deformation mechanisms of symmetric and asymmetric Σ11 tilt GBs in copper bicrystals. Different deformation mechanisms were reported, depending on GB inclination angles and equilibrium GB structures, including GB migration coupled to shear deformation, GB sliding caused by local atomic shuffling, and dislocation nucleation from GB. The simulation showed that migrating Σ11(1 1 3) GB under shear can be regarded as sliding of GB dislocations and their combination along the …

Figures Of Merit For Simultaneous Inference And Comparisons In Simulation Experiments, Noel A. Cressie, Sandy Burden

Faculty of Engineering and Information Sciences - Papers: Part A

2015 John Wiley & Sons, Ltd. This article considers the traditional figures of merit, namely, bias and mean squared (prediction) error, which are typically used to evaluate simulation experiments. We propose functions of them that account for different variables' units; these alternative figures of merit are closely tied to simultaneous multivariate inference on an unknown parameter vector or unknown state vector. Their usefulness is illustrated in a simulation experiment, where the goal is to determine the statistical properties associated with prediction of a multivariate state.

Molecular Dynamics Simulation On Generalized Stacking Fault Energies Of Fcc Metals Under Preloading Stress, Liang Zhang, Cheng Lu, A Kiet Tieu, Xing Zhao, Linqing Pei, Guillaume Michal

Faculty of Engineering and Information Sciences - Papers: Part A

Molecular dynamics (MD) simulations are performed to investigate the effects of stress on generalized stacking fault (GSF) energy of three fcc metals (Cu, Al, and Ni). The simulation model is deformed by uniaxial tension or compression in each of [111], [11-2], and [1-10] directions, respectively, before shifting the lattice to calculate the GSF curve. Simulation results show that the values of unstable stacking fault energy (γusf), stable stacking fault energy (γsf), and unstable twin fault energy (γutf) of the three elements can change with the preloaded tensile or compressive stress in different directions. The ratio of γsf/γusf, which is related …

A Round-Robin Test With Thermal Simulation Of The Welding Haz To Draw Cct Diagrams: A Need For Harmonized Procedures And Microconstituent Terminologies, Americo Scotti, Huijun Li, Rosa M. Miranda

Faculty of Engineering and Information Sciences - Papers: Part A

Thermal simulations of heat affected zone (HAZ) have been widely used. This is an economic expedite process for phase transformation evaluations in steels when subjected to weld thermal cycles as well as to draw continuous cooling transformation (CCT) diagrams. Different approaches for the simulation and parameter settings have been used by several researchers, yet leading to not always even results. Thus, it was proposed a round-robin test trial performed by different laboratories, aiming to evidence potential sources of error or inadequacy of the approaches. A High Strength Low Alloy (HSLA) steel was used as a case study. Despite the limited …

A Combined Experimental And Simulation Method For Appraising The Energy Performance Of Green Roofs In Ningbo's Chinese Climate, Georgios Kokogiannakis, Jo Darkwa, Kate Yuan

Faculty of Engineering and Information Sciences - Papers: Part A

A passive means of lowering the energy demand of buildings is the application of green roofs. The complexity between heat and moisture exchanges in green roof layers and the large variations of green roof types make the need for experimental or simulation assessments necessary for quantifying the energy benefits from green roofs. The current treatment of green roofs in simulation programs is either over-simplistic, for example by ignoring heat and moisture exchanges such as evapotranspiration, or the more advanced models have limitations and require inputs that are rarely available in practice. In this paper a combination of experimental and modelling …

Optimisation Of Size-Controllable Centroidal Voronoi Tessellation For Fem Simulation Of Micro Forming Processes, Liang Luo, Zhengyi Jiang, Haina Lu, Dongbin Wei, Kezhi Linghu, Xianming Zhao, Di Wu

Faculty of Engineering and Information Sciences - Papers: Part A

Voronoi tessellation has been employed to characterise material features in Finite Element Method (FEM) simulation, however, a poor mesh quality of the voronoi tessellations causes problems in explicit dynamic simulation of forming processes. Although centroidal voronoi tessellation can partly improve the mesh quality by homogenisation of voronoi tessellations, small features, such as short edges and small facets, lead to an inferior mesh quality. Further, centroidal voronoi tessellation cannot represent all real micro structures of materials because of the almost equal tessellation shape and size. In this paper, a density function is applied to control the size and distribution of voronoi …

Molecular Dynamics Simulation On Σ5 Grain Boundaries Of Copper Bicrystal Under Tensile And Shear Deformation, Liang Zhang, Cheng Lu, A Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part A

Molecular Dynamics simulation are employed to investigate the structures and mechanical behavior of both symmetric and asymmetric Σ5[0 0 1] tilt grain boundaries (GBs) of copper bicrystal under uniaxial tension and shear deformation. Simulation results indicate that the Σ5 asymmetric GBs can facet into their corresponding symmetric GB structures. The maximum tensile stress of symmetric GBs is higher than the asymmetric ones at both 10 K and 300 K, which suggests the symmetric GBs may have a more stable boundary structures. All the Σ5 GBs investigate in this study can migrate under the shear deformation with different velocity. The migration …

Transmob: An Agent Based Simulation Of Transport Demand And Residential Mobility In South East Sydney, Pascal Perez, Nam N. Huynh, Vu Lam Cao, Rohan Wickramasuriya, Matthew J. Berryman

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents an agent-based simulation, called TransMob, of transport demand and residential mobility in South East Sydney, Australia. In this model, each agent represents an individual resident of the study area. Each agent is given an initial travel diary. Agents are grouped in various types of household which generate social interdependencies and additional constrains on travel diaries. This initial synthetic population is then allowed to evolve for 20 years, driven by natural growth parameters, social bonding and migration rates. A micro-simulation component calculates daily traffic conditions and individual travel times, allowing for multi-modal journeys. The transport mode choice component …

An Agent Based Model For The Simulation Of Road Traffic And Transport Demand In A Sydney Metropolitan Area, Nam N. Huynh, Vu Cao, Rohan Wickramasuriya Denagamage, Matthew Berryman, Pascal Perez, Johan Barthelemy

Faculty of Engineering and Information Sciences - Papers: Part A

No abstract provided.

A Study Of Plastic Deformation Behavior During High Pressure Torsion Process By Crystal Plasticity Finite Element Simulation, Peitang Wei, Cheng Lu, A K. Tieu, Guanyu Deng

Faculty of Engineering and Information Sciences - Papers: Part A

High pressure torsion (HPT) is an efficient technique of producing ultrafine grained materials with exceptional small grain size. In this study, a crystal plasticity finite element method (CPFEM) model has been developed to investigate the plastic deformation behavior of pure aluminum single crystal during the HPT process. The simulation results show that, the distribution and evolution of the macroscopic plastic strain and the accumulative shear strain are similar. The value increases with the increase of the distance from the center as well as the number of revolution. The simulation is capable of reflecting the anisotropic characteristics of HPT deformation, a …

Concept And Simulation Study Of A Novel Localization Method For Robotic Endoscopic Capsules Using Multiple Positron Emission Markers, Trung Duc Than, Gursel Alici, Steven Harvey, Hao Zhou, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

Purpose: Over the last decade, wireless capsule endoscope has been the tool of choice for noninvasive inspection of the gastrointestinal tract, especially in the small intestine. However, the latest clinical products have not been equipped with a sufficiently accurate localization system which makes it difficult to determine the location of intestinal abnormalities, and to apply follow-up interventions such as biopsy or drug delivery. In this paper, the authors present a novel localization method based on tracking three positron emission markers embedded inside an endoscopic capsule. Methods: Three spherical 22Na markers with diameters of less than 1 mm are embedded in …

Atomistic Simulation Of Tensile Deformation Behavior Of Σ5 Tilt Grain Boundaries In Copper Bicrystal, Liang Zhang, Cheng Lu, A Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part A

Experiments on polycrystalline metallic samples have indicated that Grain boundary (GB) structure can affect many material properties related to fracture and plasticity. In this study, atomistic simulations are employed to investigate the structures and mechanical behavior of both symmetric and asymmetric ∑5[0 0 1] tilt GBs of copper bicrystal. First, the equilibrium GB structures are generated by molecular statics simulation at 0K. The results show that the ∑5 asymmetric GBs with different inclination angles (φ) are composed of only two structural units corresponding to the two ∑5 symmetric GBs. Molecular dynamics simulations are then conducted to investigate the mechanical response …