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Full-Text Articles in Social and Behavioral Sciences

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 Jan 2020

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 …


Novel Water-Based Nanolubricant With Superior Tribological Performance In Hot Steel Rolling, Hui Wu, Fanghui Jia, Zhou Li, Fei Lin, Mingshuai Huo, Shuiquan Huang, Sepidar Sayyar, Sihai Jiao, Han Huang, Zhengyi Jiang Jan 2020

Novel Water-Based Nanolubricant With Superior Tribological Performance In Hot Steel Rolling, Hui Wu, Fanghui Jia, Zhou Li, Fei Lin, Mingshuai Huo, Shuiquan Huang, Sepidar Sayyar, Sihai Jiao, Han Huang, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part B

No abstract provided.


Nonlinear Analysis Of Square Concrete-Filled Double Steel Tubular Slender Columns Incorporating Preload Effects, Mizan Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi Jan 2020

Nonlinear Analysis Of Square Concrete-Filled Double Steel Tubular Slender Columns Incorporating Preload Effects, Mizan Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Thin-walled square and circular hollow steel tubes are designed to support the permanent and construction loads of several upper composite floors before filling the concrete into the tubes to form concrete-filled double steel tubular (CFDST) columns. The influences of preloads acting on the steel tubes on the structural responses of slender square CFDST columns have not been investigated either experimentally or numerically. This paper presents a fiber-based computational model for the determination of the interaction behavior of local and global buckling in axially and eccentrically loaded CFDST thin-walled square slender columns including preload effects. The computational modeling method accounts for …


Experimental And Numerical Investigations Of Eccentrically Loaded Rectangular Concrete-Filled Double Steel Tubular Columns, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi Jan 2020

Experimental And Numerical Investigations Of Eccentrically Loaded Rectangular Concrete-Filled Double Steel Tubular Columns, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Rectangular concrete-filled double steel tubular (CFDST) columns have increasingly been utilized in high-rise buildings to support heavy loads. However, the responses of eccentrically loaded rectangular CFDST short columns have rarely been studied. This paper reports experimental and numerical investigations into the behavior of rectangular thin-walled short CFDST columns composed of a rectangular inner steel tube loaded eccentrically. Tests on rectangular and square CFDST short columns under eccentric loading and axial loading were carried out to examine their responses to various design parameters, including the cross-sectional dimensions, loading eccentricity, and width-to-thickness ratios of the external and internal tubes. The experimental program …


Experimental And Numerical Studies Of Square Concrete-Filled Double Steel Tubular Short Columns Under Eccentric Loading, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi Jan 2019

Experimental And Numerical Studies Of Square Concrete-Filled Double Steel Tubular Short Columns Under Eccentric Loading, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Square concrete-filled double steel tubular (CFDST) beam-columns consisting of an internal circular steel tube have increasingly been utilized in composite building structures because of their high structural performance. This paper describes experimental and numerical studies on the structural responses of square thin-walled CFDST columns loaded eccentrically. Tests on twenty short square CFDST columns were undertaken that included sixteen columns under eccentric loading and four columns under concentric loading. The parameters examined in the experiments included the cross-sectional dimensions, the width-to-thickness ratios of outer and internal tubes and loading eccentricity. The measured ultimate strengths, load-shortening responses, load-lateral displacement curves, stress-strain curves …


Local-Global Interaction Buckling Of Square High Strength Concrete-Filled Double Steel Tubular Slender Beam-Columns, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi Jan 2019

Local-Global Interaction Buckling Of Square High Strength Concrete-Filled Double Steel Tubular Slender Beam-Columns, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

High-strength square concrete-filled double steel tubular (CFDST) slender beam-columns with a circular internal steel tube subjected to eccentric loads may undergo interaction local-global buckling. No computational studies on the interaction local-global buckling of slender square CFDST beam-columns have been reported and their behavior has not been fully understood. This paper describes a mathematical model for the simulation of the interaction local-global buckling behavior of square high-strength CFDST slender beam-columns under axial compression in combination with uniaxial bending. The mathematical model is formulated by the fiber approach, accounting for confinement provided by the internal circular steel tube, and geometric and material …


Numerical Analysis Of Axially Loaded Rectangular Concrete-Filled Steel Tubular Short Columns At Elevated Temperatures, Ghanim Mohammed Kamil, Qing Quan Liang, Muhammad N. S Hadi Jan 2019

Numerical Analysis Of Axially Loaded Rectangular Concrete-Filled Steel Tubular Short Columns At Elevated Temperatures, Ghanim Mohammed Kamil, Qing Quan Liang, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Elevated temperatures significantly reduce the local buckling strengths of steel tubes and the ultimate strengths of rectangular concrete-filled steel tubular (CFST) columns exposed to fire. No fiber-based models have been developed that include local buckling effects on the fire-resistance of rectangular CFST columns. This paper presents a new fiber element model for the fire-resistance predictions of axially loaded rectangular CFST short columns at elevated temperatures considering local buckling. The thermal analysis problem of a CFST column is solved by the finite difference method to determine the temperature distribution within its cross-section including an air gap, concrete moisture content and the …


Numerical Analysis Of Axially Loaded Circular High Strength Concrete-Filled Double Steel Tubular Short Columns, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi Jan 2019

Numerical Analysis Of Axially Loaded Circular High Strength Concrete-Filled Double Steel Tubular Short Columns, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Circular high-strength concrete-filled double steel tubular (CFDST) columns are high performance members where the internal and external steel tubes offer significant confinement to the concrete infill. The confinement remarkably improves the concrete compressive strength and ductility. However, no fiber element models have been formulated for computing the responses of CFDST columns with circular steel tubes filled with high-strength concrete incorporating accurate confinement to the core and sandwiched concrete. In this paper, a new fiber-based numerical model is developed that computes the axial load-strain responses of circular high-strength CFDST short columns under axial loading. Based on existing experimental results, a new …


Axial-Flexural Interaction Diagram Of Rpc Columns Reinforced With Steel Fibres, Ahmed Al-Tikrite, Muhammad N. S Hadi Jan 2019

Axial-Flexural Interaction Diagram Of Rpc Columns Reinforced With Steel Fibres, Ahmed Al-Tikrite, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents analytical modelling of the axial-flexural behaviour of Reactive Powder Concrete (RPC) columns reinforced with and without steel fibres of different types (industrial and waste) in individual and hybrid forms. An analytical stress-strain model for unconfined RPC was used for the analysis of the axial loads and bending moments of the fibrous RPC columns. The layer-by-layer numerical integration method was used to calculate the axial load and bending moments in this study. The analytically developed axial load-bending moment ( P-M ) interaction diagrams were validated by using experimental results from the literature. A para- metric study was carried …


Experimental Evaluation Of Tensile Strength Test Methods For Steel Fibre-Reinforced Concrete, Hussam A. Goaiz, Nabeel Farhan, M Neaz Sheikh, Tao Yu, Muhammad N. S Hadi Jan 2019

Experimental Evaluation Of Tensile Strength Test Methods For Steel Fibre-Reinforced Concrete, Hussam A. Goaiz, Nabeel Farhan, M Neaz Sheikh, Tao Yu, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

This study presents an experimental evaluation of three different methods for determining the tensile strength of steel fibre reinforced concrete (SFRC). The test methods include the splitting test (ST), double punch test (DPT) and direct tensile test (DTT). The compressive strength of the concrete used in this study ranged between 30 and 80 MPa with 0%, 1·5% and 3% steel fibre by volume of the concrete. In total, 81 concrete cylinders were cast and tested for 28-d compressive strength, splitting tensile strength and double punch tensile strength of the concrete. In addition, 27 concrete prism specimens were cast and tested …


Effect Of Water-Based Nanolubricant Containing Nano-Tio2 On Friction And Wear Behaviour Of Chrome Steel At Ambient And Elevated Temperatures, Hui Wu, Fanghui Jia, Jingwei Zhao, Shuiquan Huang, Lianzhou Wang, Sihai Jiao, Han Huang, Zhengyi Jiang Jan 2019

Effect Of Water-Based Nanolubricant Containing Nano-Tio2 On Friction And Wear Behaviour Of Chrome Steel At Ambient And Elevated Temperatures, Hui Wu, Fanghui Jia, Jingwei Zhao, Shuiquan Huang, Lianzhou Wang, Sihai Jiao, Han Huang, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part B

A novel experimental method was developed through a ball-on-disk tribometer to study the friction and wear behaviour of a chrome steel at temperatures of 25, 200 and 500 °C. Water-based nanolubricants containing different concentrations of nano-TiO2 from 0.4 to 8.0 wt% were used to investigate their effects on friction-reduction and anti-wear mechanisms, in comparison to the benchmarks under dry and water conditions. The results show that the water-based nanolubricants can significantly reduce coefficient of friction (COF) and improve wear resistance of the chrome steel at both ambient and elevated temperatures. In particular, the use of nanolubricant containing an optimal concentration …


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 Jan 2019

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 Jan 2019

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 …


Behavior Of Eccentrically Loaded Double Circular Steel Tubular Short Columns Filled With Concrete, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi Jan 2019

Behavior Of Eccentrically Loaded Double Circular Steel Tubular Short Columns Filled With Concrete, Mizen Ahmed, Qing Quan Liang, Vipulkumar I. Patel, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Circular concrete-filled double steel tubular (CFDST) columns in high-rise building structures possess high ductility and strength performance owing to the concrete confinement exerted by the external and internal circular steel tubes. However, the behavior of circular CFDST short columns that are loaded eccentrically has not been investigated either experimentally or numerically. Particularly, numerical studies on the moment-curvature responses, strength envelopes, confinement effects and moment distributions in circular CFDST beam-columns have not been reported. In this paper, experimental and computational investigations into the structural responses of circular CFDST short columns loaded eccentrically are presented. Nineteen short circular CFDST columns with various …


Comparison Of Gmaw And Saw For Ngw Of 50 Mm Q&T Steel Plate, Druce Patrick Dunne, Willy Pang Jan 2018

Comparison Of Gmaw And Saw For Ngw Of 50 Mm Q&T Steel Plate, Druce Patrick Dunne, Willy Pang

Faculty of Engineering and Information Sciences - Papers: Part B

A one-pass-per-layer technique was used for narrow gap welding (NGW) of 50 mm thick plate of quenched and tempered steel with 690 MPa minimum yield strength. GMAW and SAW were investigated for pulsed and non-pulsed welding using the same 1.2 mm strength-matching welding consumable and the same nominal heat inputs for each of the pulsed and non-pulsed welds. The welds were defect-free and the hardness, tensile strength and Charpy impact energies were generally consistent with high weldment integrity. Pulsing of the welding current had the effect of slightly increasing side-wall fusion, flattening the weld bead and decreasing its volume. The …


Performance Evaluation And Lubrication Mechanism Of Water-Based Nanolubricants Containing Nano-Tio2 In Hot Steel Rolling, Hui Wu, Jingwei Zhao, Liang Luo, Shuiquan Huang, Lianzhou Wang, Suoquan Zhang, Sihai Jiao, Han Huang, Zhengyi Jiang Jan 2018

Performance Evaluation And Lubrication Mechanism Of Water-Based Nanolubricants Containing Nano-Tio2 In Hot Steel Rolling, Hui Wu, Jingwei Zhao, Liang Luo, Shuiquan Huang, Lianzhou Wang, Suoquan Zhang, Sihai Jiao, Han Huang, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part B

Hot rolling tests of a low-alloy steel were conducted at a rolling temperature of 850 °C under different lubrication conditions, including benchmarks (dry condition and water) and water-based nanolubricants containing different concentrations of nano-TiO2 from 1.0 to 8.0 wt%. The effects of nanolubricants on rolling force, surface roughness, thickness of oxide scale, and microstructure were systematically investigated through varying nano-TiO2 concentrations. The results show that the application of nanolubricants can decrease the rolling force, surface roughness and oxide scale thickness of rolled steels, and refine ferrite grains. In particular, the nanolubricant containing an optimal concentration (4.0 wt%) of …


Nonlinear Analysis Of Circular High Strength Concrete-Filled Stainless Steel Tubular Slender Beam-Columns, Vipulkumar I. Patel, Qing Quan Liang, Muhammad N. S Hadi Jan 2017

Nonlinear Analysis Of Circular High Strength Concrete-Filled Stainless Steel Tubular Slender Beam-Columns, Vipulkumar I. Patel, Qing Quan Liang, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

Concrete-filled stainless steel tubular (CFSST) slender columns are increasingly used in composite structures owing to their distinguished features, such as aesthetic appearance, high corrosion resistance, high durability and ease of maintenance. Currently, however, there is a lack of an accurate and efficient numerical model that can be utilized to determine the performance of circular CFSST slender columns. This paper describes a nonlinear fiber-based model proposed for computing the deflection and axial load-moment strength interaction responses of eccentrically loaded circular high-strength CFSST slender columns. The fiber-based model incorporates the accurate three-stage stress-strain relations of stainless steels, accounting for different strain hardening …


Behavior Of Self-Compacting Concrete Columns Reinforced Longitudinally With Steel Tubes, Muhammad N. S Hadi, Faez Alhussainy, M Neaz Sheikh Jan 2017

Behavior Of Self-Compacting Concrete Columns Reinforced Longitudinally With Steel Tubes, Muhammad N. S Hadi, Faez Alhussainy, M Neaz Sheikh

Faculty of Engineering and Information Sciences - Papers: Part B

This study investigates the behavior of self-compacting concrete (SCC) specimens reinforced with small-diameter steel tubes in lieu of reinforcing bars. Twenty specimens were cast and tested. Four specimens were reinforced with normal steel bars (reference specimens) and the remaining 16 with steel tubes. All specimens contained steel helices with a pitch of either 50 mm or 75 mm. Deformed steel bars of 16-mm diameter were used in the four reference specimens as longitudinal reinforcement. Steel tubes of 33.7-mm outside diameter with 2-mm wall thickness (ST33.7) and steel tubes of 26.9-mm outside diameter with 2.6-mm wall thickness (ST26.9) were used as …


Strain-Induced Ferrite Formation And Its Effect On Mechanical Properties Of A Dual Phase Steel Produced Using Laboratory Simulated Strip Casting, Zhiping Xiong, Ahmed A. Saleh, Andrii Kostryzhev, Elena V. Pereloma Jan 2017

Strain-Induced Ferrite Formation And Its Effect On Mechanical Properties Of A Dual Phase Steel Produced Using Laboratory Simulated Strip Casting, Zhiping Xiong, Ahmed A. Saleh, Andrii Kostryzhev, Elena V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part B

Thermo-mechanical processing of a strip cast dual phase (DP) steel was carried out using a Gleeble thermo-mechanical simulator. The effect of deformation temperatures in the range from 1050 to 700 °C on the microstructure evolution was investigated using optical, scanning and transmission electron microscopy along with electron backscattering diffraction (EBSD). Strain-induced ferrite (SIF) formation was observed following austenite deformation (∼0.41 reduction) in the 800–700 °C temperature range, leading to a ferrite grain refinement down to 3.1 ± 2.3 μm. A novel segmentation procedure was applied to separate selected EBSD maps into polygonal ferrite, SIF and second phase regions (bainite/martensite). Following …


Displaced Hardness Peak Phenomenon In Heat-Affected Zone Of Welded Quenched And Tempered Em812 Steel, Druce P. Dunne, W Pang Jan 2017

Displaced Hardness Peak Phenomenon In Heat-Affected Zone Of Welded Quenched And Tempered Em812 Steel, Druce P. Dunne, W Pang

Faculty of Engineering and Information Sciences - Papers: Part A

Investigations of microstructural and hardness gradients in the heat-affected zone (HAZ) of quenched and tempered (Q&T) steels have indicated that peak hardness does not occur in the grain-coarsened heat-affected zone (GCHAZ) adjacent to the fusion boundary, which is typical of ferritic steels, but corresponds more closely to the grain-refined region (GRHAZ). This phenomenon, the displaced hardness peak (DHP) effect, is considered to arise when the hardenability of the steel is high enough to result in the same microstructure in the GC and GR heat-affected zones, except for significant refinement of the microstructure of the GRHAZ, which increases the hardness and …


Nonlinear Analysis Of Biaxially Loaded Rectangular Concrete-Filled Stainless Steel Tubular Slender Beam-Columns, Vipulkumar I. Patel, Qing Quan Liang, Muhammad N. S Hadi Jan 2017

Nonlinear Analysis Of Biaxially Loaded Rectangular Concrete-Filled Stainless Steel Tubular Slender Beam-Columns, Vipulkumar I. Patel, Qing Quan Liang, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

Rectangular concrete-filled stainless steel tubular (CFSST) beam-columns utilized as supporting members for building frames may experience axial compression and biaxial moments. A numerical simulation considering the local buckling effects for thin-walled rectangular CFSST slender beam-columns has not been performed. This paper reports a stability modeling on the structural characteristics of rectangular CFSST slender beam-columns accounting for different strain-hardening of stainless steel under tension and compression. The influences of local buckling are considered in the simulation utilizing the existing effective width formulations. The developed numerical model simulates the strength interaction and load-deflection behavior of CFSST slender beam-columns. Comparisons of computed results …


Analysis Of Tio2 Nano-Additive Water-Based Lubricants In Hot Rolling Of Microalloyed Steel, Hui Wu, Jingwei Zhao, Wenzhen Xia, Xiawei Cheng, Anshun He, Jung-Ho Yun, Lianzhou Wang, Han Huang, Sihai Jiao, Li Huang, Suoquan Zhang, Zhengyi Jiang Jan 2017

Analysis Of Tio2 Nano-Additive Water-Based Lubricants In Hot Rolling Of Microalloyed Steel, Hui Wu, Jingwei Zhao, Wenzhen Xia, Xiawei Cheng, Anshun He, Jung-Ho Yun, Lianzhou Wang, Han Huang, Sihai Jiao, Li Huang, Suoquan Zhang, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part B

No abstract provided.


Experimental Investigation Of Composite Beams Reinforced With Gfrp I-Beam And Steel Bars, Muhammad N. S Hadi, Jiansong Yuan Jan 2017

Experimental Investigation Of Composite Beams Reinforced With Gfrp I-Beam And Steel Bars, Muhammad N. S Hadi, Jiansong Yuan

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents results of an experimental study on the flexural behaviour of a composite beam, which is reinforced with longitudinal tensile steel bars as well as glass fibre reinforced polymer (GFRP) pultruded I-beam encased in concrete. Five beam specimens, including one traditional reinforced concrete (RC) beam and four composite beams, were cast and tested under four-point bending. The variables involved in the composite beams include the type of longitudinal tensile bars (steel bars and GFRP bars) and the location of the I-beam in the cross-section (middle and a shift of 30 mm towards the tension region). The test results …


Hybrid Structure Of White Layer In High Carbon Steel - Formation Mechanism And Its Properties, Rumana Hossain, Farshid Pahlevani, Evelien Witteveen, Amborish Banerjee, Bill Joe, B Prusty, Rian J. Dippenaar, Veena Sahajwalla Jan 2017

Hybrid Structure Of White Layer In High Carbon Steel - Formation Mechanism And Its Properties, Rumana Hossain, Farshid Pahlevani, Evelien Witteveen, Amborish Banerjee, Bill Joe, B Prusty, Rian J. Dippenaar, Veena Sahajwalla

Faculty of Engineering and Information Sciences - Papers: Part B

This study identifies for the first time, the hybrid structure of the white layer in high carbon steel and describes its formation mechanism and properties. The so-called 'white layer' in steel forms during high strain rate deformation and appears featureless under optical microscopy. While many researchers have investigated the formation of the white layer, there has been no definitive study, nor is there sufficient evidence to fully explain the formation, structure and properties of the layer. In this study, the formation, morphology and mechanical properties of the white layer was determined following impact testing, using a combination of optical and …


Effects Of Oil-In-Water Based Nanolubricant Containing Tio2 Nanoparticles In Hot Rolling Of 304 Stainless Steel, Wenzhen Xia, Jingwei Zhao, Hui Wu, Xianming Zhao, Xiaoming Zhang, Jianzhong Xu, Sihai Jiao, Zhengyi Jiang Jan 2017

Effects Of Oil-In-Water Based Nanolubricant Containing Tio2 Nanoparticles In Hot Rolling Of 304 Stainless Steel, Wenzhen Xia, Jingwei Zhao, Hui Wu, Xianming Zhao, Xiaoming Zhang, Jianzhong Xu, Sihai Jiao, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part B

Energy saving and improvement of product quality are of crucial importance in hot rolling of 304 stainless steel. In this paper, oil-in-water (O/W) based nanolubricants containing TiO2 nanoparticles were developed to reduce the rolling force and improve the surface quality of rolled 304 stainless steel product. Practical hot rolling tests with and without application of lubricant were conducted to systematically investigate the effects of the developed O/W based nanolubricants on the rolling force, surface roughness, oxide scale thickness and tribological behaviour. The obtained results indicate that the nanoparticles can enter the deform zone with oil droplets to take a …


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 Jan 2016

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 …


Combined Bearing And Shear-Out Capacity Of Structural Steel Bolted Connections, Lip H. Teh, Mehmet Eren Uz Jan 2016

Combined Bearing And Shear-Out Capacity Of Structural Steel Bolted Connections, Lip H. Teh, Mehmet Eren Uz

Faculty of Engineering and Information Sciences - Papers: Part A

This study is concerned with the strength limit state of serial bolted connections in structural steel plates. It points out that the ultimate load capacity of a serial bolted connection failing in combined bearing and shear-out cannot be computed as the simple sum of the respective ultimate bearing and ultimate shear-out capacities, which is implicitly permitted in design specifications worldwide. Based on the laboratory test results of 10 hot-rolled steel plate specimens composed of three different grades with nominal thicknesses ranging from 5 to 8 mm, the paper first establishes the ultimate bearing coefficient of a 20-mm bolted connection in …


Shape Optimisation Of Cold-Formed Steel Columns With Manufacturing Constraints Using The Hough Transform, Bin Wang, Benoit P. Gilbert, Adrien M. Molinier, Hong Guan, Lip H. Teh Jan 2016

Shape Optimisation Of Cold-Formed Steel Columns With Manufacturing Constraints Using The Hough Transform, Bin Wang, Benoit P. Gilbert, Adrien M. Molinier, Hong Guan, Lip H. Teh

Faculty of Engineering and Information Sciences - Papers: Part A

This paper introduces manufacturing constraints into a recently developed evolutionary algorithm for shape optimisation of CFS profiles. The algorithm is referred to as "self-shape optimisation" and uses Genetic Algorithm (GA) together with the Augmented Lagrangian (AL) method to avoid ill-conditioned problems. Simple manufacturing rules derived from the limitations of current cold-forming processes, i.e. a limited ability to form continuously curved surfaces without discrete bends, are described in the paper and incorporated into the algorithm. The Hough transform is used to detect straight lines and transform arbitrarily drawn cross-sections into manufacturable ones. Firstly, the algorithm is verified against a known optimisation …


Microstructures And Mechanical Properties Of Trip Steel Produced By Strip Casting Simulated In The Laboratory, Zhiping Xiong, Andrii Kostryzhev, Ahmed A. Saleh, Liang Chen, Elena V. Pereloma Jan 2016

Microstructures And Mechanical Properties Of Trip Steel Produced By Strip Casting Simulated In The Laboratory, Zhiping Xiong, Andrii Kostryzhev, Ahmed A. Saleh, Liang Chen, Elena V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

Conventional transformation induced plasticity (TRIP) steel (0.17C-1.52Si-1.61Mn-0.03Al, wt%) was produced via strip casting technology simulated in the laboratory. Effects of holding temperature, holding time and cooling rate on ferrite formation were studied via analysis of the continuous cooling transformation diagram obtained here. A typical microstructure for conventional TRIP steels consisting of ~ 0.55 fraction of polygonal ferrite with bainite, retained austenite and martensite was obtained. However, coarse prior austenite grain size of ~80 μm led to large polygonal ferrite grain size of ~17 μm, coarse second phase regions of ~21 μm size, small amount of retained austenite (0.02-0.045) and the …


On The Feasibility Of Partial Slip Reversal And De-Twinning During The Cyclic Loading Of Twip Steel, Ahmed A. Saleh, Bjorn Clausen, Donald W. Brown, Elena V. Pereloma, Christopher H. J Davies, Carlos N. Tome, Azdiar A. Gazder Jan 2016

On The Feasibility Of Partial Slip Reversal And De-Twinning During The Cyclic Loading Of Twip Steel, Ahmed A. Saleh, Bjorn Clausen, Donald W. Brown, Elena V. Pereloma, Christopher H. J Davies, Carlos N. Tome, Azdiar A. Gazder

Faculty of Engineering and Information Sciences - Papers: Part A

A recently modified Elasto-Plastic Self-Consistent (EPSC) model which empirically accounts for both intergranular and intragranular back stresses has been successfully used to simulate the cyclic (tension-compression) loading behaviour of an Fe-24Mn-3Al-2Si-1Ni-0.06C TWinning Induced Plasticity (TWIP) steel between strain limits of ±1%. Lattice strain measurements acquired via in-situ neutron diffraction were used to further validate the modelling results. An improved prediction of the pronounced Bauschinger effect during unloading is achieved when the reversibility of partial slip in the 〈112〉 direction is accounted for. This result indicates a potential contribution of the stress-induced separation of partial dislocations to the observed early yielding …