Science and Technology Studies Commons^™

Performance Evaluation Of Intermittently Cfrp Wrapped Square And Circularised Square Reinforced Concrete Columns Under Different Loading Conditions, Anh Duc Mai, M Neaz Sheikh, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents the results of an experimental investigation on square and circularised square rein-forced concrete (RC) columns intermittently wrapped with carbon fibre reinforced polymer (CFRP)under different loading conditions. Twelve RC specimens consisting of eight square RC specimenswith 150mm150mm cross-section and 800mm height and four circularised square RC specimenswith 212mm diameter and 800 mm height were tested under concentric axial load, eccentric axialload and four-point flexural load. The test results showed that intermittent wrapping increased thestrength and ductility of square RC specimens. The test results also showed that circularisation com-bined with intermittent wrapping significantly improved the strength and ductility of …

Accurate Range Estimation For An Electric Vehicle Including Changing Environmental Conditions And Traction System Efficiency, Kaveh Sarrafan, Danny Sutanto, Kashem M. Muttaqi, Graham Town

Faculty of Engineering and Information Sciences - Papers: Part B

Range anxiety is an obstacle to the acceptance of electric vehicles (EVs), caused by drivers' uncertainty regarding their vehicle's state of charge (SoC) and the energy required to reach their destination. Most estimation methods for these variables use simplified models with many assumptions that can result in significant error, particularly if dynamic and environmental conditions are not considered. For example, the combined efficiency of the inverter drive and electric motor varies throughout the route and is not constant as assumed in most range estimation methods. This study proposes an improved method for SoC and range estimation by taking into account …

Driver Alerting System Using Range Estimation Of Electric Vehicles In Real Time Under Dynamically Varying Environmental Conditions, Vincent R. Tannahill, Kashem M. Muttaqi, Danny Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

As the technology supporting electric vehicles (EVs) is rapidly progressing and the cost of EV components is reducing, EVs are becoming more feasible for use in Australia and in many countries around the world. However, the public perception of EVs and their perceived limitations result in a slow uptake of the technology, partially because of the uncertainty regarding the ability of an EV to meet the driving needs of the general population. Range anxiety is a particular concern with drivers having fear of being stranded by a depleted EV battery. This study explores means of reducing range anxiety by taking …

Coke Degradation Under Simulated Blast Furnace Conditions, Xing Xing, Harold P. Rogers, Guangqing Zhang, Kim Hockings, Paul Zulli, Oleg Ostrovski

Faculty of Engineering and Information Sciences - Papers: Part A

Three metallurgical cokes made from coking coals over a significant range in rank were subjected to treatment with blast furnace-like gas composition-temperature profile to 1 673 K, annealing under N2 to 2 273 K and gasification with subsequent annealing at 1 873 and 2 273 K. The degradation of cokes after reaction and annealing was characterised using I-drum tumbling, tensile testing, ultra-micro indentation and X-ray diffraction. Both gasification and annealing decreased the mechanical strength of coke. Compared with annealing at 1 673 K, gasification at same temperature caused larger degradation for all three cokes, and the effect was more significant …

Experimental Study On Frp Tube Reinforced Concrete Columns Under Different Loading Conditions, Weiqiang Wang, M Neaz Sheikh, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

The behavior of fiber-reinforced polymer (FRP) tube reinforced concrete (FTRC) columns under different loading conditions was investigated in this study. Four groups of 16 specimens were cast and tested. Specimens in the first group (the reference group) were re- inforced with longitudinal steel bars and steel helices (Group REF). Specimens in the second group were reinforced with intact glass FRP tubes (Group IT). Specimens in the third group were also reinforced with intact glass FRP tubes. In addition, polymer grid was embedded into the concrete cover to reduce the cover spalling (Group ITG). Specimens in the fourth group were reinforced …

Wearable Vibrotactile Biofeedback Device Allowing Identification Of Different Floor Conditions For Lower-Limb Amputees, Anson Wan, Duo Wong, Christina Ma, Ming Zhang, Winson Lee

Faculty of Engineering and Information Sciences - Papers: Part A

Objective

To evaluate a newly developed biofeedback device enabling lower-limb amputees to identify various floor conditions.

Design

Self-control with repeated measures (with and without the biofeedback device) within the amputee group, and group control comparing between amputee and nonamputee groups.

Setting

University locomotion laboratory.

Participants

Five lower-limb amputees and 8 nonamputees (N=13).

Interventions

A wearable biofeedback device, which identified different floor conditions by analyzing the force patterns under the prosthetic feet and provided vibration cues in response to different floor conditions, was provided to the amputees.

Main Outcome Measures

The subjects stepped on a foam platform concealing a small object …

Effects Of Sintering Materials And Gas Conditions On Formation Of Silico-Ferrites Of Calcium And Aluminium During Iron Ore Sintering, Zhe Wang, David J. Pinson, Sheng Chew, Brian J. Monaghan, Mark Pownceby, Nathan A.S. Webster, Harold P. Rogers, Guangqing Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

Silico-ferrites of calcium and aluminium (SFCA) are desirable phases in a high quality iron ore sinter product. The effects of sintering temperature, CaO/SiO2 ratio, sintering gas atmosphere and cooling procedure on the phase composition of sintered specimens from an industrial sinter blend were examined with focus on the formation of SFCA phases. The proportions of mineral phases in specimens sintered at 1 250-1 325°C were quantitatively examined using image analysis. SFCA can be formed at low temperatures by solid state reactions, the formation of which was enhanced by increasing temperature. Further increasing sintering temperature promoted the reduction of Fe3+ in …

Removal Of Bisphenol A And Diclofenac By A Novel Fungal Membrane Bioreactor Operated Under Non-Sterile Conditions, Shufan Yang, Faisal I. Hai, Long D. Nghiem, Luong N. Nguyen, Felicity Roddick, William E. Price

Faisal I Hai

Previous studies have confirmed significant removal of various trace organic contaminants (TrOCs) by white-rot fungal cultures under sterile batch test conditions. However, little is known about TrOC removal in continuous flow fungal reactors in a non-sterile environment. This study reports the removal of two TrOCs, namely, bisphenol A and diclofenac, by a fungal membrane bioreactor (MBR).

Influence Of Loading Conditions During Tensile Testing On Acoustic Emission, Turbadrakh Chuluunbat, Cheng Lu, Andrii Kostryzhev, A Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part A

The Acoustic Emission (AE) monitoring technique is widely used in mechanical and material research for detection of plastic deformation, fracture initiation and crack growth. However, the influence of AE features (such as signal amplitude, frequency, rise time and duration) on the fracture parameters (such as brittle or ductile mode of propagation and fracture propagation speed) is not completely understood. In this paper, the effect of loading conditions on fracture behavior was studied using AE monitoring during tensile testing of an aluminum alloy specimen. The fracture development was observed using a high speed video camera and was analyzed using the finite …

Calibrating Markov Chain-Based Deterioration Models For Predicting Future Conditions Of Railway Bridge Elements, Niroshan Walgama Wellalage, Tieling Zhang, Richard Dwight

Faculty of Engineering and Information Sciences - Papers: Part A

Existing nonlinear optimization-based algorithms for estimating Markov transition probability matrix (TPM) in bridge deterioration modeling sometimes fail to find optimum TPM values, and hence lead to invalid future condition prediction. In this study, a Metropolis-Hasting algorithm (MHA)-based Markov chain Monte Carlo (MCMC) simulation technique is proposed to overcome this limitation and calibrate the state-based Markov deterioration models (SBMDM) of railway bridge components. Factors contributing to rail bridge deterioration were identified; inspection data for 1,000 Australian railway bridges over 15 years were reviewed and filtered. The TPMs corresponding to a typical bridge element were estimated using the proposed MCMC simulation method …

Macrostrength And Pore Structure Of Coke Subjected To Gasification And Annealing Under Blast Furnace Conditions, Xing Xing, Harold P. Rogers, Guangqing Zhang, Paul Zulli, Oleg Ostrovski

Faculty of Engineering and Information Sciences - Papers: Part A

Metallurgical cokes were subjected to gasification by CO-CO2-N2 gas with blast furnace-like composition-temperature profile to 1400 °C and annealing under N2 at temperature up to 2000 °C. The degradation of coke strength following reaction and annealing was characterised using tensile testing. Both gasification and annealing decreased the mechanical strength of coke. Degradation of all examined cokes by gasification at 1400 °C was stronger in comparison with annealing at the same temperature.

A Tool To Estimate The Wheel/Rail Contact And Temperature Rising Under Dry, Wet And Oily Conditions, Khoa Vo, A Kiet Tieu, Hongtao Zhu, Prabuono Buyung Kosasih

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, finite element method (FEM) has been applied to evaluate the wheel/rail contact stress under different contact conditions. The elastic-plastic model coded in ANSYS/LS-DYNA includes a whole wheel, 680 mm of the canted rail, and sub-components of the track (railpads, sleepers, and ballast). The three values of friction coefficient 0.4, 0.2 and 0.07 have been chosen to model the dry, wet and oily environmental contacts, respectively. The high mechanical stresses exerted at the contact area will cause the temperature rise, which results in decreasing of the yield strength of the wheel/rail. The growth of temperature is a major …

Effects Of Hydrogen On The Critical Conditions For Dynamic Recrystallization Of Titanium Alloy During Hot Deformation, Jingwei Zhao, Hua Ding, Zhengyi Jiang, Dongbin Wei, Kezhi Linghu

Faculty of Engineering and Information Sciences - Papers: Part A

Hot deformation tests were performed to study the flow behavior and microstructural evolution of a Ti600 titanium alloy with different hydrogen contents. The effects of hydrogen on the critical conditions for the initiation of dynamic recrystallization (DRX) were investigated. The DRX kinetics models of hydrogenated Ti600 alloy were developed, and the DRX volume fractions were quantified under different deformation conditions. The results indicate that the addition of proper hydrogen (no greater than 0.3 pct) benefits the decrease of both the critical stress and critical strain for the initiation of DRX. The critical stress and critical strain are dependent linearly on …

Variational Inequality Model For Cordon-Based Congestion Pricing Under Side Constrained Stochastic User Equilibrium Conditions, Zhiyuan Liu, Qiang Meng, Shuaian Wang

Faculty of Engineering and Information Sciences - Papers: Part A

A major objective of the practical implemented cordon-based congestion pricing schemes is to maintain the traffic conditions within the cordon area, which is rarely considered in most of the existing studies. Thus, this paper addresses the optimal toll charge pattern that can restrict the total inbound flow of each cordon to a predetermined threshold. The toll charges on all the entry links of one cordon are required to be identical, for the ease of implementation and users' recognition. The users' route choice behaviour is assumed to follow stochastic user equilibrium (SUE) with asymmetric link travel time functions. It is shown …

Flicker Mitigation Strategy For Dfigs During Variable Wind Conditions, Lasantha Meegahapola, Brendan Fox, Damian Flynn

Dr Lasantha G Meegahapola

This paper presents a flicker mitigation scheme for the doubly-fed induction generator (DFIG) during variable wind conditions. The flicker mitigation strategy was developed based on the distribution line X/R ratio and the active power deviation from the average active power during variable wind conditions. Flicker emission was analyzed using a flicker meter based on the IEC standards. Both short-term and long-term flicker severities were analyzed during the time period of study. The flicker mitigation strategy was evaluated under different system conditions such as X/R ratio, distribution line length, shortcircuit capacity (SCC), and wind variability. It is shown that the proposed …

Optimal Power Flow With Variable Wind Conditions, S Durairaj, L Meegahapola, D Flynn, B Fox

Dr Lasantha G Meegahapola

This paper presents simulation studies of an electric arc furnace (EAF) model in the MATLAB/SIMULINK environment. EAF was modeled as a current source controlled by a non-linear resistance. Voltage flicker, a phenomenon of annoying light intensity fluctuation, caused by EAF, has been a major power quality concern for both power companies and customers. A model was developed for the electric arc furnace and it was applied in the simulation studies of distribution static synchronous compensator (DSTATCOM) for voltage flicker mitigation. The controller for DSTATCOM was designed based on DQ-model for the reactive power management which helps in the mitigation of …

Voltage And Power Quality Improvement Strategy For A Dfig Wind Farm During Variable Wind Conditions, L Meegahapola, T Littler, B Fox, J Kennedy, D Flynn

Dr Lasantha G Meegahapola

This paper presents a voltage and power quality enhancement scheme for a doubly-fed induction generator (DFIG) wind farm during variable wind conditions. The wind profiles were derived considering the measured data at a DFIG wind farm located in Northern Ireland (NI). The aggregated DFIG wind farm model was validated using measured data at a wind farm during variable generation. The voltage control strategy was developed considering the X/R ratio of the wind farm feeder which connects the wind farm and the grid. The performance of the proposed strategy was evaluated for different X/R ratios, and wind profiles with different characteristics. …

Optical Solitary Waves In Thermal Media With Non-Symmetric Boundary Conditions, Simon Louis, Timothy R. Marchant, Noel F. Smyth

Tim Marchant

Optical spatial solitary waves are considered in a nonlocal thermal focusing medium with non-symmetric boundary conditions. The governing equations consist of a nonlinear Schrödinger equation for the light beam and a Poisson equation for the temperature of the medium. Three numerical methods are investigated for calculating the ground and excited solitary wave solutions of the coupled system. It is found that the Newton conjugate gradient method is the most computationally efficient and versatile numerical technique. The solutions show that by varying the ambient temperature, the solitary wave is deflected towards the warmer boundary. Solitary wave stability is also examined both …

Effects Of Tungsten Addition And Heat Treatment Conditions On Microstructure And Mechanical Properties Of Microalloyed Forging Steels, Jingwei Zhao, Zhengyi Jiang, Chong Soo Lee

Faculty of Engineering and Information Sciences - Papers: Part A

In the present work, the effects of tungsten (W) addition and heat treatment conditions on the microstructure, impact toughness and tensile properties of microalloyed forging steels were studied. Four kinds of microalloyed forging steels were produced by varying W additions (0, 0.5, 1 and 2 wt%). Heat treatment was carried out at temperatures ranging from 840 to 950 °C followed by air and furnace cooling. Mechanical tests were used to evaluate the room temperature Charpy impact and tensile properties. The resulting microstructures were analysed via optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show …

Removal Of Bisphenol A And Diclofenac By A Novel Fungal Membrane Bioreactor Operated Under Non-Sterile Conditions, Shufan Yang, Faisal I. Hai, Long D. Nghiem, Luong N. Nguyen, Felicity Roddick, William E. Price

Faculty of Engineering and Information Sciences - Papers: Part A

Previous studies have confirmed significant removal of various trace organic contaminants (TrOCs) by white-rot fungal cultures under sterile batch test conditions. However, little is known about TrOC removal in continuous flow fungal reactors in a non-sterile environment. This study reports the removal of two TrOCs, namely, bisphenol A and diclofenac, by a fungal membrane bioreactor (MBR).

Microstructural Characterization Of P91 Steel In The Virgin, Service Exposed And Post-Service Re-Normalized Conditions, Huijun Li, David Mitchell

Faculty of Engineering and Information Sciences - Papers: Part A

P91 steel has been widely used in power generation industry. Generally, P91 creep resisting steel is produced by normalizing and tempering. The normalizing temperature is in the range of 1040–10808C and tempering temperature is in the range of 750–7808C. The microstructure after tempering is tempered martensite with precipitates of carbides, M23C6, and vanadium/niobium rich carbo‐nitride of the type MX (M ¼ V or Nb and X ¼ C or N). The presence of carbide precipitates improves creep rupture strength due to precipitation hardening. The carbide coarsening and microstructure degradation during service will result in deterioration in creep strength. It is …

Unstable Willmore Surfaces Of Revolution Subject To Natural Boundary Conditions, Anna Dall'acqua, Klaus Deckelnick, Glen Wheeler

Faculty of Engineering and Information Sciences - Papers: Part A

In the class of surfaces with fixed boundary, critical points of the Willmore functional are naturally found to be those solutions of the Euler-Lagrange equation where the mean curvature on the boundary vanishes. We consider the case of symmetric surfaces of revolution in the setting where there are two families of stable solutions given by the catenoids. In this paper we demonstrate the existence of a third family of solutions which are unstable critical points of the Willmore functional, and which spatially lie between the upper and lower families of catenoids. Our method does not require any kind of smallness …

Fully Nonlinear Curvature Flow Of Axially Symmetric Hypersurfaces With Boundary Conditions, James Mccoy, Fatemah Mofarreh, Graham Williams

Faculty of Engineering and Information Sciences - Papers: Part A

Inspired by earlier results on the quasilinear mean curvature flow, and recent investigations of fully nonlinear curvature flow of closed hypersurfaces which are not convex, we consider contraction of axially symmetric hypersurfaces by convex, degree-one homogeneous fully nonlinear functions of curvature. With a natural class of Neumann boundary conditions, we show that evolving hypersurfaces exist for a finite maximal time. The maximal time is characterised by a curvature singularity at either boundary. Some results continue to hold in the cases of mixed Neumann-Dirichlet boundary conditions and more general curvature-dependent speeds.

Coke Microstructure And Strength Under Blast Furnace Conditions, Xing Xing, Guangqing Zhang, Harold Rogers, Paul Zulli, Oleg Ostrovski

Faculty of Engineering and Information Sciences - Papers: Part A

No abstract provided.

Optical Solitary Waves In Thermal Media With Non-Symmetric Boundary Conditions, Simon Louis, Timothy R. Marchant, Noel F. Smyth

Faculty of Engineering and Information Sciences - Papers: Part A

Optical spatial solitary waves are considered in a nonlocal thermal focusing medium with non-symmetric boundary conditions. The governing equations consist of a nonlinear Schrödinger equation for the light beam and a Poisson equation for the temperature of the medium. Three numerical methods are investigated for calculating the ground and excited solitary wave solutions of the coupled system. It is found that the Newton conjugate gradient method is the most computationally efficient and versatile numerical technique. The solutions show that by varying the ambient temperature, the solitary wave is deflected towards the warmer boundary. Solitary wave stability is also examined both …

Flicker Mitigation Strategy For Dfigs During Variable Wind Conditions, Lasantha Meegahapola, Brendan Fox, Damian Flynn

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a flicker mitigation scheme for the doubly-fed induction generator (DFIG) during variable wind conditions. The flicker mitigation strategy was developed based on the distribution line X/R ratio and the active power deviation from the average active power during variable wind conditions. Flicker emission was analyzed using a flicker meter based on the IEC standards. Both short-term and long-term flicker severities were analyzed during the time period of study. The flicker mitigation strategy was evaluated under different system conditions such as X/R ratio, distribution line length, shortcircuit capacity (SCC), and wind variability. It is shown that the proposed …

Development Of Hydraulic Fracturing In High Stress Conditions In Australian Underground Coal Mines, Dennis John Black, Naj Aziz

Faculty of Engineering and Information Sciences - Papers: Part A

Hydraulic fracturing has been used extensively in the petroleum and coalbed methane industries as a means of improving access to the reservoir and thereby enhancing production. In the Australian coal mining industry there has been an aversion to the use of hydraulic fracturing. One of the main reasons for the lack of application of this technology has been the perceived risk of damage to the strata and the resulting impact on future mining operations. A number of Australian mines are progressing toward areas where gas drainage is becoming increasingly difficult and these mines are seriously considering the use of hydraulic …