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Full-Text Articles in Engineering

Triboelectric Nanogenerator Versus Piezoelectric Generator At Low Frequency (<4 Hz): A Quantitative Comparison, Abdelsalam Ahmed, Islam Hassan, Ahmed Helal, Vitor Sencadas, Ali Radhi, Chang Jeong, Maher El-Kady Jan 2020

Triboelectric Nanogenerator Versus Piezoelectric Generator At Low Frequency (<4 Hz): A Quantitative Comparison, Abdelsalam Ahmed, Islam Hassan, Ahmed Helal, Vitor Sencadas, Ali Radhi, Chang Jeong, Maher El-Kady

Faculty of Engineering and Information Sciences - Papers: Part B

© 2020 The Author(s) Triboelectric nanogenerators (TENGs) and piezoelectric generators (PGs) are generally considered the two most common approaches for harvesting ambient mechanical energy that is ubiquitous in our everyday life. The main difference between the two generators lies in their respective working frequency range. Despite the remarkable progress, there has been no quantitative studies on the operating frequency band of the two generators at frequency values below 4 Hz, typical of human motion. Here, the two generators are systematically compared based on their energy harvesting capabilities below 4 Hz. Unlike PGs, the TENG demonstrates higher power performance and is …


Air Void Detection Using Variational Mode Decomposition With Low Rank, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Shivakumar Karekal Jan 2020

Air Void Detection Using Variational Mode Decomposition With Low Rank, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Shivakumar Karekal

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents an air-void detection technique for air-coupled radar, which emits electromagnetic waves to interrogate an air-void inside a medium or between two media. The reflections from the air-medium interfaces are usually corrupted by air-coupling, antenna ringing, and internal reflections, rendering air-void detection very difficult or, in certain cases, impossible. The proposed method exploits the low-rank structure of the background clutter to suppress these nuisance signals. A variational mode decomposition model is developed to extract the backscattering at different air-medium interfaces as signal modes. Real experiments are conducted using a stepped frequency radar. The experimental results show that the …


Parsimonious Network Based On A Fuzzy Inference System (Panfis) For Time Series Feature Prediction Of Low Speed Slew Bearing Prognosis, Wahyu Caesarendra, Mahardhika Pratama, Buyung Kosasih, Tegoeh Tjahjowidodo, Adam Glowacz Jan 2018

Parsimonious Network Based On A Fuzzy Inference System (Panfis) For Time Series Feature Prediction Of Low Speed Slew Bearing Prognosis, Wahyu Caesarendra, Mahardhika Pratama, Buyung Kosasih, Tegoeh Tjahjowidodo, Adam Glowacz

Faculty of Engineering and Information Sciences - Papers: Part B

In recent years, the utilization of rotating parts, e.g., bearings and gears, has been continuously supporting the manufacturing line to produce a consistent output quality. Due to their critical role, the breakdown of these components might significantly impact the production rate. Prognosis, which is an approach that predicts the machine failure, has attracted significant interest in the last few decades. In this paper, the prognostic approaches are described briefly and advanced predictive analytics, namely a parsimonious network based on a fuzzy inference system (PANFIS), is proposed and tested for low speed slew bearing data. PANFIS differs itself from conventional prognostic …


Integrated Condition Monitoring And Prognosis Method For Incipient Defect Detection And Remaining Life Prediction Of Low Speed Slew Bearings, Wahyu Caesarendra, Tegoeh Tjahjowidodo, Buyung Kosasih, Anh Kiet Tieu Jan 2017

Integrated Condition Monitoring And Prognosis Method For Incipient Defect Detection And Remaining Life Prediction Of Low Speed Slew Bearings, Wahyu Caesarendra, Tegoeh Tjahjowidodo, Buyung Kosasih, Anh Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents an application of multivariate state estimation technique (MSET), sequential probability ratio test (SPRT) and kernel regression for low speed slew bearing condition monitoring and prognosis. The method is applied in two steps. Step (1) is the detection of the incipient slew bearing defect. In this step, combined MSET and SPRT is used with circular-domain kurtosis, time-domain kurtosis, wavelet decomposition (WD) kurtosis, empirical mode decomposition (EMD) kurtosis and the largest Lyapunov exponent (LLE) feature. Step (2) is the prediction of the selected features' trends and the estimation of the remaining useful life (RUL) of the slew bearing. In …


Relationship Between Indoor Air Temperatures And Energy Bills For Low Income Homes In Australia, Clayton Mcdowell, Georgios Kokogiannakis, Laia Ledo Gomis, Paul Cooper Jan 2017

Relationship Between Indoor Air Temperatures And Energy Bills For Low Income Homes In Australia, Clayton Mcdowell, Georgios Kokogiannakis, Laia Ledo Gomis, Paul Cooper

Faculty of Engineering and Information Sciences - Papers: Part B

Energy poverty is a prevalent issue in Australia and other countries across the globe especially for people with a low income. This paper seeks to investigate the relationship of energy consumption and indoor air temperatures and is separated into 3 sections; a comparison of actual electricity consumption to energy benchmarks provided by the Australian Energy Regulator, monitoring results of living room air temperature for the winter of 2015, and an analysis of living room air temperatures versus electricity consumption. The results of a comparison of electricity consumption of 119 low income elderly peoples (60+) dwellings to that of the energy …


Radar Imaging Of Stationary Indoor Targets Using Joint Low-Rank And Sparsity Constraints, Van Ha Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive Jan 2016

Radar Imaging Of Stationary Indoor Targets Using Joint Low-Rank And Sparsity Constraints, Van Ha Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive

Faculty of Engineering and Information Sciences - Papers: Part A

This paper introduces a joint low-rank and sparsity-based model to address the problem of wall-clutter mitigation in compressed through-the-wall radar imaging. The proposed model is motivated by two observations that wall reflections reside in a low-rank subspace, and target signals tend to be sparse. In the proposed approach, the task of segregating target returns from wall reflections is formulated as a joint low-rank and sparsity constrained optimization problem. Here, the low rank constraint is imposed on the wall component and the sparsity constraint is used to model the target component. An iterative soft thresholding algorithm is developed to estimate a …


Analysis Of Bacterial Diversity In Two Oil Blocks From Two Low-Permeability Reservoirs With High Salinities, Meng Xiao, Shan Shan Sun, Zhong Zhi Zhang, Junming Wang, Long Wei Qiu, Hua Yang Sun, Zhaozheng Song, Beiyu Zhang, De Li Gao, Guangqing Zhang, Wei Min Wu Jan 2016

Analysis Of Bacterial Diversity In Two Oil Blocks From Two Low-Permeability Reservoirs With High Salinities, Meng Xiao, Shan Shan Sun, Zhong Zhi Zhang, Junming Wang, Long Wei Qiu, Hua Yang Sun, Zhaozheng Song, Beiyu Zhang, De Li Gao, Guangqing Zhang, Wei Min Wu

Faculty of Engineering and Information Sciences - Papers: Part A

The community diversities of two oil reservoirs with low permeability of 1.81 x 10 '3 and 2.29 x 10 '3 1/4m 2 in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher …


Indoor Scene Reconstruction For Through-The-Wall Radar Imaging Using Low-Rank And Sparsity Constraints, Van H. Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive Jan 2016

Indoor Scene Reconstruction For Through-The-Wall Radar Imaging Using Low-Rank And Sparsity Constraints, Van H. Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive

Faculty of Engineering and Information Sciences - Papers: Part A

This paper addresses the problem of indoor scene reconstruction in compressed sensing through-the-wall radar imaging. The proposed method is motivated by two observations that wall reflections reside in a low-rank subspace and the imaged scene tends to be sparse. The task of mitigating the wall reflections and reconstructing an image of the scene behind-the-wall is cast as a joint low-rank and sparsity constrained optimization problem, where a low-rank matrix captures the wall returns and a sparse matrix represents the formed image. An iterative algorithm is developed to estimate the low-rank matrix and the sparse scene vector from a reduced measurement …


Transient Cfd Modelling Of Low-Temperature Spontaneous Heating Behaviour In Multiple Coal Stockpiles With Wind Forced Convection, Jian Zhang, Yuntao Liang, Ting X. Ren, Zhongwei Wang, Gongda Wang Jan 2016

Transient Cfd Modelling Of Low-Temperature Spontaneous Heating Behaviour In Multiple Coal Stockpiles With Wind Forced Convection, Jian Zhang, Yuntao Liang, Ting X. Ren, Zhongwei Wang, Gongda Wang

Faculty of Engineering and Information Sciences - Papers: Part A

Spontaneous heating of coal stockpile has long been a thermal dynamic hazard during coal storage, processing, and transport. A transient non-equilibrium thermal CFD model has been developed to study the low-temperature self-heating behaviour of coal in multiple stockpiles under different prevailing wind conditions. Modelling results from the initial steady wind flow simulation indicate that a wake region can be induced on the leeward side of each coal stockpile. Pressure coefficient drops when the wind stream encounters or leaves a stockpile and the pressure coefficient profiles of multiple stockpiles tend to have more resemblance with a wider spacing. The first stockpile …


Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi Jan 2015

Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a simple methodology to improve the low voltage ride-through (LVRT) capability of Doubly Fed Induction Generator (DFIG) based wind turbines in order to ride through higher voltage sags and durations. The proposed method is based on selection of an appropriate value for DC side super capacitor (SC) in such a way that it could help wind turbine for LVRT without any need to crowbar protection. The operation of SC based wind turbine in normal and fault conditions is simulated using MATLAB/SIMULINK. The simulation results show that the proposed method can be used effectively for LVRT improvement and …


Characteristics Of Power Quality Disturbances In Australia: Voltage Dips At Low-Voltage Sites, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, Sarath Perera, Philip Ciufo, Gerrard M. Drury Jan 2015

Characteristics Of Power Quality Disturbances In Australia: Voltage Dips At Low-Voltage Sites, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, Sarath Perera, Philip Ciufo, Gerrard M. Drury

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage dips are considered to be one of the costliest of all power quality disturbances due to their disruption of industrial and commercial operations. The ability to characterise the voltage dip performance of distribution networks has many benefits for industry. There is considerable potential for industry to make large economic gains if voltage dip behaviour can be better understood and planned for. To put strategies in place to deal with voltage dips, there is a need for extensive data collection and analysis so that correct planning decisions can be made. This study details the characteristics of voltage dip data which …


Voltage Sag Compensation Of Point Of Common Coupling For Low Voltage Ride-Through Enhancment Of Inverter Interfaced Dg Using Bridge Type Fcl, Seyed Behzad Naderi, Michael Negnevitsky, Amin Jalilian, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi Jan 2015

Voltage Sag Compensation Of Point Of Common Coupling For Low Voltage Ride-Through Enhancment Of Inverter Interfaced Dg Using Bridge Type Fcl, Seyed Behzad Naderi, Michael Negnevitsky, Amin Jalilian, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

Fully converter wind turbines and solar power utilise an inverter to connect to grid. The inverters are vulnerable to voltage sag in their terminal due to its damaging effect on semiconductor self-Turnoff switches. In this paper, a bridge-Type fault current limiter (B-FCL) is proposed for low voltage ride-Through (LVRT) of the inverters during different types of fault with simple control system. The proposed B-FCL is capable to compensate the voltage sag in point of common coupling (PCC) and makes a safe condition not only for the inverter but also for any equipment which has been connected to the PCC in …


Interface Analysis And Hot Deformation Behaviour Of A Novel Laminated Composite With High-Cr Cast Iron And Low Carbon Steel Prepared By Hot Compression Bonding, Zhengyi Jiang, Xingjian Gao, Sheng-Li Li, Hong Mei Zhang, Dengfu Chen, Jian Zhong Xu Jan 2015

Interface Analysis And Hot Deformation Behaviour Of A Novel Laminated Composite With High-Cr Cast Iron And Low Carbon Steel Prepared By Hot Compression Bonding, Zhengyi Jiang, Xingjian Gao, Sheng-Li Li, Hong Mei Zhang, Dengfu Chen, Jian Zhong Xu

Faculty of Engineering and Information Sciences - Papers: Part A

A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron (HCCI) as the inner layer and low carbon steel (LCS) as the outer layers on a Gleeble 3500 thermomechanical simulator at a temperature of 950 °C and a strain rate of 0.001 S-1. Interfacial bond quality and hot deformation behaviour of the laminate were studied by microstructural characterisation and mechanical tests. Experimental results show that the metallurgical bond between the constituent metals was achieved under the proposed bonding conditions without discernible defects and the formation of interlayer or intermetallic layer …


Application Of The Largest Lyapunov Exponent Algorithm For Feature Extraction In Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Prabuono Buyung Kosasih, A Kiet Tieu, Craig A. S Moodie Jan 2015

Application Of The Largest Lyapunov Exponent Algorithm For Feature Extraction In Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Prabuono Buyung Kosasih, A Kiet Tieu, Craig A. S Moodie

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a new application of the largest Lyapunov exponent (LLE) algorithm for feature extraction method in low speed slew bearing condition monitoring. The LLE algorithm is employed to measure the degree of non-linearity of the vibration signal which is not easily monitored by existing methods. The method is able to detect changes in the condition of the bearing and demonstrates better tracking of the progressive deterioration of the bearing during the 139 measurement days than comparable methods such as the time domain feature methods based on root mean square (RMS), skewness and kurtosis extraction from the raw vibration …


Comparative Evaluation Of Modern Dosimetry Techniques Near Low- And High-Density Heterogeneities, Eyad A. Alhakeem, Sami Alshaikh, Anatoly B. Rosenfeld, Sergei F. Zavgorodni Jan 2015

Comparative Evaluation Of Modern Dosimetry Techniques Near Low- And High-Density Heterogeneities, Eyad A. Alhakeem, Sami Alshaikh, Anatoly B. Rosenfeld, Sergei F. Zavgorodni

Faculty of Engineering and Information Sciences - Papers: Part A

The purpose of this study is to compare performance of several dosimetric methods in heterogeneous phantoms irradiated by 6 and 18 MV beams. Monte Carlo (MC) calculations were used, along with two versions of Acuros XB, anisotropic analytical algorithm (AAA), EBT2 film, and MOSkin dosimeters. Percent depth doses (PDD) were calculated and measured in three heterogeneous phantoms. The first two phantoms were a 30 x 30 x 30 cm3 solid-water slab that had an air-gap of 20x 2.5 x 2.35 cm3. The third phantom consisted of 30 x 30 x 5 cm3 solid water slabs, two 30 x 30 x …


Effect Of Pre-Quenching Process On Microstructure And Mechanical Properties In A Nb-Microalloyed Low Carbon Q-P Steel, Jun Zhang, Hua Ding, Jingwei Zhao Jan 2015

Effect Of Pre-Quenching Process On Microstructure And Mechanical Properties In A Nb-Microalloyed Low Carbon Q-P Steel, Jun Zhang, Hua Ding, Jingwei Zhao

Faculty of Engineering and Information Sciences - Papers: Part A

A refined microstructure consisting of martensite and retained austenite at room temperature has been produced in a Nb-microalloyed low carbon Si-Mn steel by a novel heat-treatment, pre-quenching prior to quenching and partitioning processes (Q&Q-P). The results showed that compared with the conventional quenching and partitioning steel the mechanical properties of steel obtained by the novel treatment have been significantly improved, with a good combination of ultimate tensile strength (1000MPa) and total elongation (above 30%). Meanwhile, the volume fraction of retained austenite has been increased. It was found that the improvement of mechanical properties was mainly attributed to the enhanced TRIP …


High Rate Serially Concatenated Codes With Low Error Floors, Bo Liu, Sheng Tong, Qinghua Guo, Jun Tong, Jiangtao Xi, Yanguang Yu Jan 2015

High Rate Serially Concatenated Codes With Low Error Floors, Bo Liu, Sheng Tong, Qinghua Guo, Jun Tong, Jiangtao Xi, Yanguang Yu

Faculty of Engineering and Information Sciences - Papers: Part A

Serial concatenation of Hamming codes and an accumulator has been shown to achieve near capacity performance at high code rates. However, these codes usually exhibit poor error floor performance due to their small minimum distances. To overcome this weakness, we propose to replace the outer Hamming codes by product codes constructed from Hamming codes and single-parity-check codes. In this way, the minimum distance of the outer code can be doubled, which is expected to increase the minimum distance of the serially concatenated code and thus to improve error floor performance. Three-dimensional EXIT chart is used for their convergence analysis and …


An Application Of Mathematical Morphology Operators As Features Extraction Method For Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Dwi B. Wibowo, Mochammad Ariyanto, Joga D. Setiawan Jan 2015

An Application Of Mathematical Morphology Operators As Features Extraction Method For Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Dwi B. Wibowo, Mochammad Ariyanto, Joga D. Setiawan

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a new application of mathematical morphology (MM) operators for low speed slew bearing condition monitoring. The MM operators were used as a signal processing step and feature extraction method for bearing vibration signals. Four basic MM operators; erosion, dilation, closing and opening, were studied. This paper also investigates another potential MM operator, namely gradient operator. Two common time domain features in bearing condition monitoring, namely root mean square (RMS) and kurtosis, were extracted from the processed signal. The study shows that the changes in bearing condition can be clearly detected from the extracted features (RMS and kurtosis) …


Adaptive And Robust Feature Selection For Low Bitrate Mobile Augmented Reality Applications, Yi Cao, Christian H. Ritz, Raad Raad Jan 2014

Adaptive And Robust Feature Selection For Low Bitrate Mobile Augmented Reality Applications, Yi Cao, Christian H. Ritz, Raad Raad

Faculty of Engineering and Information Sciences - Papers: Part A

Mobile augmented reality applications rely on automatically matching a captured visual scene to an image in a database. This is typically achieved by deriving a set of features for the captured image, transmitting them through a network and then matching with features derived for a database of reference images. A fundamental problem is to select as few and robust features as possible such that the matching accuracy is invariant to distortions caused by camera capture whilst minimising the bit rate required for their transmission. In this paper, novel feature selection methods are proposed, based on the entropy of the image …


Low-Energy Positron And Electron Scattering From Tetrahydrofuran And 3-Hydroxy-Tetrahydrofuran, James P. Sullivan, Luca Chiari, Emma Anderson, Wade Tattersall, Prasanga Palihawadana, J R. Machacek, Casten Makochekanwa, R P. Mceachran, Stephen J. Buckman, M J. Brunger, Gustavo Garcia, Francisco Blanco Jan 2014

Low-Energy Positron And Electron Scattering From Tetrahydrofuran And 3-Hydroxy-Tetrahydrofuran, James P. Sullivan, Luca Chiari, Emma Anderson, Wade Tattersall, Prasanga Palihawadana, J R. Machacek, Casten Makochekanwa, R P. Mceachran, Stephen J. Buckman, M J. Brunger, Gustavo Garcia, Francisco Blanco

Faculty of Engineering and Information Sciences - Papers: Part A

We present new cross section results from a joint experimental and theoretical investigation into low-energy positron and electron scattering from two targets of biological interest, namely tetrahydrofuran and 3-hydroxy-tetrahydrofuran. We compare and discuss the total, elastic and inelastic cross sections for these species in the light of potential positron and electron-induced damage in biomolecular systems.


Study On Hot-Working Behavior Of High Carbon Steel / Low Carbon Steel Composite Material Using Processing Map, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Dengfu Chen Jan 2014

Study On Hot-Working Behavior Of High Carbon Steel / Low Carbon Steel Composite Material Using Processing Map, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Dengfu Chen

Faculty of Engineering and Information Sciences - Papers: Part A

The high carbon steel (HCS)/low carbon steel (LCS) laminated composite made by centrifugal casting technology was subjected to hot compression tests on Gleeble 3500 thermomechanical simulator in a range of temperatures (800-1100 oC) and strain rates (0.02-10 s-1). The hot-working behavior of the laminate was characterised by analysing the flow stress-strain curves and constructing the processing map based on dynamic materials model via superimposing efficiency of power dissipation and flow instability maps. The safe and unsafe processing conditions were identified in the processing map which was validated by microstructural examinations. Banded microstructure and micro-shear cracks occurred in the unsafe domains …


Low-Energy Electron Scattering From Α-Tetrahydrofurfuryl Alcohol, Luca Chiari, Darryl Jones, Penny Thoi, Michael J. Brungei, Gustavo Garcia, Francisco Blanco Jan 2014

Low-Energy Electron Scattering From Α-Tetrahydrofurfuryl Alcohol, Luca Chiari, Darryl Jones, Penny Thoi, Michael J. Brungei, Gustavo Garcia, Francisco Blanco

Faculty of Engineering and Information Sciences - Papers: Part A

We report on differential cross section results for low-energy electron collisions with the biologically relevant species a-tetrahydrofurfuryl alcohol. Electron-impact excitation measurements of the electronic states of a-tetrahydrofurfuryl alcohol were carried out at incident energies between 15-50 eV and for scattering angles in the range 20-90 degrees. Elastic differential cross section have also been calculated within the Independent Atom Model and using the Screening Corrected Additivity Rule approach at selected energies between 1-1000 eV.


Grainscan: A Low Cost, Fast Method For Grain Size And Colour Measurements, Alex P. Whan, Alison Smith, C R. Cavanagh, Jean-Philippe F. Ral, Lindsay M. Shaw, Crispin A. Howitt, Leanne Bischof Jan 2014

Grainscan: A Low Cost, Fast Method For Grain Size And Colour Measurements, Alex P. Whan, Alison Smith, C R. Cavanagh, Jean-Philippe F. Ral, Lindsay M. Shaw, Crispin A. Howitt, Leanne Bischof

Faculty of Engineering and Information Sciences - Papers: Part A

Background: Measuring grain characteristics is an integral component of cereal breeding and research into genetic control of seed development. Measures such as thousand grain weight are fast, but do not give an indication of variation within a sample. Other methods exist for detailed analysis of grain size, but are generally costly and very low throughput. Grain colour analysis is generally difficult to perform with accuracy, and existing methods are expensive and involved. Results: We have developed a software method to measure grain size and colour from images captured with consumer level flatbed scanners, in a robust, standardised way. The accuracy …


Analysis Of Fishscaling Resistance Of Low Carbon Heavy Plate Steels, Aiwen Zhang, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Chun Xu Jan 2014

Analysis Of Fishscaling Resistance Of Low Carbon Heavy Plate Steels, Aiwen Zhang, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Chun Xu

Faculty of Engineering and Information Sciences - Papers: Part A

The precipitates and hydrogen permeation behavior in three kinds of hot rolled low carbon heavy plate steels for enameling were analyzed; then, both sides of the steels were enameled. The experimental results show that a large amount of coarse Ti4C2S2 and fine Ti(C, N) particles exist in the optimized Ti-bearing steel, quite a lot of fine Ti(C, N) particles exist in the optimized carbon steel, but only a little bit fine Ti(C, N) particles exist in the carbon steel. The fishscaling resistance of the steels can be correlated to the effective hydrogen diffusion coefficient, and a model of correlation between …


Circular Domain Features Based Condition Monitoring For Low Speed Slewing Bearing, Wahyu Caesarendra, Prabuono Buyung Kosasih, A Kiet Tieu, Craig A. S Moodie Jan 2014

Circular Domain Features Based Condition Monitoring For Low Speed Slewing Bearing, Wahyu Caesarendra, Prabuono Buyung Kosasih, A Kiet Tieu, Craig A. S Moodie

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a novel application of circular domain features calculation based condition monitoring method for low rotational speed slewing bearing. The method employs data reduction process using piecewise aggregate approximation (PAA) to detect frequency alteration in the bearing signal when the fault occurs. From the processed data, circular domain features such as circular mean, circular variance, circular skewness and circular kurtosis are calculated and monitored. It is shown that the slight changes of bearing condition during operation can be identified more clearly in circular domain analysis compared to time domain analysis and other advanced signal processing methods such as …


Constitutive Analysis For Hot Deformation Behaviour Of Novel Bimetal Consisting Of Pearlitic Steel And Low Carbon Steel, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Huijun Li, Sihai Jiao, Jianzhong Xu, Xiaoming Zhang, Jingtao Han, Dengfu Chen Jan 2014

Constitutive Analysis For Hot Deformation Behaviour Of Novel Bimetal Consisting Of Pearlitic Steel And Low Carbon Steel, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Huijun Li, Sihai Jiao, Jianzhong Xu, Xiaoming Zhang, Jingtao Han, Dengfu Chen

Faculty of Engineering and Information Sciences - Papers: Part A

To understand the high temperature flow behaviour of a novel pearlitic steel (PS) and low carbon steel (LCS) bimetal, hot compression tests in a wide range of temperature and strain rate were conducted on a Gleeble 3500 thermo mechanical simulator, and the constitutive model was developed based on the experimental data. The measured true stress-strain curves exhibited three types of variation patterns, which are (i) a plateau type, (ii) single peak type and (iii) multi peaks type. These patterns well displayed the effects of the deformation temperature, strain rate and plastic strain on the flow behaviour of the bimetal. By …


Crack Healing In A Low-Carbon Steel Under Hot Plastic Deformation, Hailiang Yu, Xianghua Liu, Xinwen Li, Ajit R. Godbole Jan 2014

Crack Healing In A Low-Carbon Steel Under Hot Plastic Deformation, Hailiang Yu, Xianghua Liu, Xinwen Li, Ajit R. Godbole

Faculty of Engineering and Information Sciences - Papers: Part A

The behavior of internal crack healing in low-carbon steel samples undergoing hot plastic deformation was investigated using the MMS 200 thermo-mechanical simulator. The characterization of cracks after plastic deformation was analyzed using scanning electron microscopy under different heating temperatures, reduction ratios, numbers of deformation passes, strain rates, and holding time durations. It was found that the degree of crack healing increases with increasing heating temperature, reduction ratio, and holding time duration, and with decreasing number of deformation passes and strain rate.


Computational Analysis Of Compressive Strain Hardening Exponents Of Bimetal With Pearlitic Steel And Low Carbon Steel, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Jingtao Han Jan 2014

Computational Analysis Of Compressive Strain Hardening Exponents Of Bimetal With Pearlitic Steel And Low Carbon Steel, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Jingtao Han

Faculty of Engineering and Information Sciences - Papers: Part A

The compressive strain hardening behaviour of a novel bimetal with pearlitic steel and low carbon steel was investigated by computational analysis based on the isothermal compression tests in a wide range of deformation temperature and strain rate. The Hollomon's equation was employed to calculate the strain hardening exponent (SHE) with the assistance of mathematical manipulation. The result shows that the logarithmic relationship between the flow stress and plastic strain of the bimetal is highly non-linear, which results in the variation of the SHE of the bimetal. This variation reflects the dynamic competition between the strain hardening and softening mechanism by …


Effects Of Temperature And Strain Rate On Microstructure And Mechanical Properties Of High Chromium Cast Iron/Low Carbon Steel Bimetal Prepared By Hot Diffusion-Compression Bonding, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Dengfu Chen, Jianzhong Xu, Xiaoming Zhang, Dianyao Gong Jan 2014

Effects Of Temperature And Strain Rate On Microstructure And Mechanical Properties Of High Chromium Cast Iron/Low Carbon Steel Bimetal Prepared By Hot Diffusion-Compression Bonding, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Dengfu Chen, Jianzhong Xu, Xiaoming Zhang, Dianyao Gong

Faculty of Engineering and Information Sciences - Papers: Part A

The objective of this study is to develop a hot diffusion-compression bonding process for cladding low carbon steel (LCS) to high chromium cast iron (HCCI) in solid-state. The influence of temperature (950-1150 degrees C) and strain rate (0.001-1 s (1)) on microstructure, hardness and bond strength of the HCCI/LCS bimetal were investigated. The interface microstructure reveals that the unbonded region can only be found for 950 degrees C due to lack of diffusion, while the intergrowth between the constituent metals occurred at and above 1100 degrees C. When bonding temperature increases to 1150 degrees C, a carbide-free zone was observed …


Degradation Trend Estimation And Prognosis Of Large Low Speed Slewing Bearing Lifetime, Prabuono Buyung Kosasih, Wahyu Caesarendra, Kiet Tieu, Achmad Widodo, Craig A. S Moodie Jan 2014

Degradation Trend Estimation And Prognosis Of Large Low Speed Slewing Bearing Lifetime, Prabuono Buyung Kosasih, Wahyu Caesarendra, Kiet Tieu, Achmad Widodo, Craig A. S Moodie

Faculty of Engineering and Information Sciences - Papers: Part A

In many applications, degradation of bearing conditions is usually monitored by changes in time-domain features. However, in low speed (< 10 rpm) slewing bearing, these changes are not easily detected because of the low energy and low frequency of the vibration. To overcome this problem, a combined low pass filter (LPF) and adaptive line enhancer (ALE) signal preconditioning method is used. Time-domain features such as root mean square (RMS), skewness and kurtosis are extracted from the output signal of the combined LPF and ALE method. The extracted features show accurate information about the incipient of fault as compared to extracted features from the original vibration signal. This information then triggers the prognostic algorithm to predict the remaining lifetime of the bearing. The algorithm used to determine the trend of the nonstationary data is auto-regressive integrated moving average (ARIMA).