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Full-Text Articles in Social and Behavioral Sciences
Nonlinear Analysis Of Circular High Strength Concrete-Filled Stainless Steel Tubular Slender Beam-Columns, Vipulkumar I. Patel, Qing Quan Liang, Muhammad N. S Hadi
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 …
Axial Load-Bending Moment Diagrams Of Gfrp Reinforced Columns And Gfrp Encased Square Columns, Jim Youssef, Muhammad N. S Hadi
Axial Load-Bending Moment Diagrams Of Gfrp Reinforced Columns And Gfrp Encased Square Columns, Jim Youssef, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
Fiber reinforced polymer (FRP) pultruded materials are available in a wide variety of shapes, including bars, I-sections, C-sections and other structural sections. Due to their high durability, low self-weight and reduced maintenance costs, these FRP materials are becoming a competitive option for replacing steel as structural materials especially in corrosive environments. This paper summarizes an experimental program on the axial and flexural behaviour of square concrete members reinforced with glass fiber reinforced polymer (GFRP) bars and embedded with pultruded GFRP structural sections under different loading conditions. Furthermore, an analytical model is presented to predict the axial load-bending moment interaction diagrams …
Axial And Flexural Behavior Of Unreinforced And Frp Bar Reinforced Circular Concrete Filled Frp Tube Columns, Muhammad N. S Hadi, Qasim Khan, M Neaz Sheikh
Axial And Flexural Behavior Of Unreinforced And Frp Bar Reinforced Circular Concrete Filled Frp Tube Columns, Muhammad N. S Hadi, Qasim Khan, M Neaz Sheikh
Faculty of Engineering and Information Sciences - Papers: Part A
Fiber Reinforced Polymer (FRP) composites have emerged as a viable alternative of steel reinforcement due to higher ultimate tensile strength to weight ratio and corrosion resistance of FRP composites. Concrete Filled Fiber Reinforced Polymer Tube (CFFT) technique for new column construction has attracted significant research attention. This paper investigated the axial and flexural behavior of concrete filled Carbon FRP (CFRP) tube columns with and without CFRP bar and concrete filled Glass FRP (GFRP) tube columns with and without GFRP bar. The test results of 16 circular CFFT and four steel Reinforced Concrete (RC) specimens of 203-205 mm diameter and 800-812 …
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
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 …
Experimental Study On Frp Tube Reinforced Concrete Columns Under Different Loading Conditions, Weiqiang Wang, M Neaz Sheikh, Muhammad N. S Hadi
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 …
Compressive Behavior Of Frp-Confined Concrete-Encased Steel Columns, Tao Yu, G Lin, Shi Shun Zhang
Compressive Behavior Of Frp-Confined Concrete-Encased Steel Columns, Tao Yu, G Lin, Shi Shun Zhang
Faculty of Engineering and Information Sciences - Papers: Part A
FRP-confined concrete-encased steel I-section columns (FCSCs) are an emerging form of hybrid columns. An FCSC consists of an outer FRP tube, an encased steel section and a concrete infill. The FCSCs possess many advantages over conventional reinforced concrete columns, including the excellent corrosion resistance, excellent ductility and ease for construction. Existing studies on FCSCs, however, have been rather limited. This paper presents a combined experimental and theoretical study on the behavior of FCSCs under concentric and eccentric compression. The experimental program included the testing of a total of 14 specimens, with the main variables being the section configuration, the thickness …
Cyclic Lateral Response Of Frp-Confined Circular Concrete-Filled Steel Tubular Columns, Tao Yu, Y M. Hu, Jin Guang Teng
Cyclic Lateral Response Of Frp-Confined Circular Concrete-Filled Steel Tubular Columns, Tao Yu, Y M. Hu, Jin Guang Teng
Faculty of Engineering and Information Sciences - Papers: Part A
Concrete-filled steel tubular (CFT) columns are widely used as columns in many structural systems and a common failure mode of such tubular columns is inelastic outward local buckling near a column end. The use of fibre-reinforced polymer (FRP) jackets/wraps for the suppression of such local buckling has recently been proposed and has been proven to possess excellent potential in both retrofit/strengthening and new construction. This paper presents the results of an experimental study into the behaviour of large-scale FRP-confined CFT (CCFT) columns under combined axial compression and lateral loading. The test parameters included the stiffness of the FRP jacket and …
Confinement Model For Frp Confined Normal- And High-Strength Concrete Circular Columns, Thong M. Pham, Muhammad N. S Hadi
Confinement Model For Frp Confined Normal- And High-Strength Concrete Circular Columns, Thong M. Pham, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
This study establishes a confinement model for FRP confined normal- and high-strength concrete circular columns. A new column parameter was suggested for estimating the compressive strength of FRP confined concrete. The proposed model is able to predict the ultimate condition of FRP confined concrete columns that have similar unconfined concrete strength and confining pressure but significant differences in the jacket stiffness. The proposed model was then verified using a database of 574 FRP confined concrete circular columns with different types of FRP. This database covers unconfined concrete strength between 15 MPa and 170 MPa and specimens with a diameter ranging …
Behaviour Of Gfrp Tube Reinforced Concrete Columns Under Axial Compression, Weiqiang Wang, M Neaz Sheikh, Muhammad N. S Hadi, Blake Lyons
Behaviour Of Gfrp Tube Reinforced Concrete Columns Under Axial Compression, Weiqiang Wang, M Neaz Sheikh, Muhammad N. S Hadi, Blake Lyons
Faculty of Engineering and Information Sciences - Papers: Part A
This paper reports the result of an experimental investigation on the behaviour of Glass Fibre Reinforced Polymer (GFRP) tube reinforced concrete columns under axial compression. The GFRP tube was placed into the concrete to provide reinforcement both in the longitudinal and transverse directions. In this study, a total of 8 columns with 150 mm diameter and 300 mm height were cast and tested under axial compression. The columns were divided into four groups and each group contains two identical columns. The first group had two columns of plain concrete, and the remaining three groups were reinforced with solid, axially perforated …
Nonlinear Analysis Of Axially Loaded Cicular Concrete-Filled Stainless Steel Tubular Short Columns, Vipulkumar Patel, Qing Quan Liang, Muhammad N. S Hadi
Nonlinear Analysis Of Axially Loaded Cicular Concrete-Filled Stainless Steel Tubular Short Columns, Vipulkumar Patel, Qing Quan Liang, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
The experiments indicate that stainless steels in tension deform plastically more than stainless steels in compression. Therefore, the strain hardening of stainless steels in compression is much faster than that of stainless steels in tension. The full-range two-stage constitutive model for stainless steels assumes that stainless steels follow the same stress-strain behavior in compression and tension, which may underestimate the compressive strength of stainless steel tubes. This paper presents a fiber element model incorporating the recently developed full-range three-stage stress-strain relationships based on experimentally observed behavior for stainless steels for the nonlinear analysis of circular concrete-filled stainless steel tubular (CFSST) …
Numerical Analysis Of High-Strength Concrete-Filled Steel Tubular Slender Beam-Columns Under Cyclic Loading, Vipulkumar Patel, Qing Quan Liang, Muhammad N. S Hadi
Numerical Analysis Of High-Strength Concrete-Filled Steel Tubular Slender Beam-Columns Under Cyclic Loading, Vipulkumar Patel, Qing Quan Liang, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
The effects of cyclic local buckling on the behavior of concrete-filled steel tubular (CFST) slender beam-columns under cyclic loading were approximately considered in existing analytical methods by modifying the stress– strain curve for the steel tube in compression. These methods, however, cannot simulate the progressive cyclic local buckling of the steel tubes. This paper presents a new efficient numerical model for predicting the cyclic performance of high strength rectangular CFST slender beam-columns accounting for the effects of progressive cyclic local buckling of steel tube walls under stress gradients. Uniaxial cyclic constitutive laws for the concrete core and steel tubes are …
Spline-Shape Modification For Frp-Confined Concrete Columns: Theory And Evaluation, Muhammad N. S Hadi, Xu Lei
Spline-Shape Modification For Frp-Confined Concrete Columns: Theory And Evaluation, Muhammad N. S Hadi, Xu Lei
Faculty of Engineering and Information Sciences - Papers: Part A
The confinement efficiency for FRP-confined square concrete columns is relatively low compared to circular columns due to a large area of ineffectively-confined concrete and stress concentration at sharp corners. Shape modification of square concrete columns has been proposed but modifying the shape of cross-section from a square to a circle results in a significant increase in crosssectional area and self-weight of the columns, which raises new issues and is not practical when the space in the structure is limited. To address the abovementioned issues, a spline-shaped cross-section is proposed in this study as a target shape for shape modification. A …
Behaviour Of Hollow Core Square Reinforced Concrete Columns Wrapped With Cfrp With Different Fibre Orientations, Muhammad N. Hadi, T D. Le
Behaviour Of Hollow Core Square Reinforced Concrete Columns Wrapped With Cfrp With Different Fibre Orientations, Muhammad N. Hadi, T D. Le
Faculty of Engineering and Information Sciences - Papers: Part A
Results of testing twelve hollow core square reinforced concrete columns wrapped with Carbon fibre 33 reinforced polymer (CFRP) are presented. The effect of fibre orientation on the performance of specimens 34 under concentric and eccentric loads was investigated. Twelve specimens were divided into four groups with three 36 specimens each. The specimens in the first reference group were unwrapped, while the specimens in the 37 remaining groups were wrapped with CFRP of different wrap combinations of three fibre orientations.The specimens in each group were tested 39 under three eccentricities: 0 (concentric), 25, and 50 mm up to failure. Test results …
Performance Of Cfrp Wrapped Square Reinforced Concrete Columns Subjected To Eccentric Loading, Ida Bagus Rai Widiarsa, Muhammad N. S Hadi
Performance Of Cfrp Wrapped Square Reinforced Concrete Columns Subjected To Eccentric Loading, Ida Bagus Rai Widiarsa, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
Strengthening concrete columns with fibre-reinforced polymers (FRP) has been studied extensively, but the majority of published studies have focused on circular columns. Most concrete columns in the field have square or rectangular cross sections and resist eccentric loading as well. The objective of this study is to investigate the performance of square reinforced concrete (RC) columns wrapped with carbon FRP subjected to eccentric loading. The influence of two parameters was studied including the number of FRP layers and the magnitude of eccentricity. Compression testing was conducted on twelve short square RC columns wrapped with CFRP composites. The columns had a …
Strengthening Square Reinforced Concrete Columns By Circularisation And Frp Confinement, Thong Minh Pham, Viet Le Doan, Muhammad N. Hadi
Strengthening Square Reinforced Concrete Columns By Circularisation And Frp Confinement, Thong Minh Pham, Viet Le Doan, Muhammad N. Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
A technique called circularisation where segmental circular concrete covers made of different concrete strengths (40 MPa, 80 MPa and 100 MPa) was used to change a square column to a circular column. The applicability of the circularisation method was experimentally studied for a wide range of concrete strengths (from 40 MPa to 100 MPa). The behaviour of the strengthened specimens under different loading conditions including concentric loading, eccentric loading (25 mm and 50 mm) and flexural bending is investigated. The experimental results demonstrate that using high strength concrete (HSC) for the additional covers to strengthen existing square reinforced concrete (RC) …
Confinement Effect Of Frp And Transverse Steel On Retrofitting Square Concrete Columns, Le V. Doan, Xu Lei, Muhammad N. S Hadi, Thong M. Pham
Confinement Effect Of Frp And Transverse Steel On Retrofitting Square Concrete Columns, Le V. Doan, Xu Lei, Muhammad N. S Hadi, Thong M. Pham
Faculty of Engineering and Information Sciences - Papers: Part A
This study presents an experimental investigation into strain distribution of Fibre-Reinforced Polymer (FRP) in FRP-confined concrete columns with internal steel reinforcement under concentric and eccentric loading conditions. A total of nine reinforced concrete columns were cast and tested. Three of them were square in cross-section while the others were originally square but were shape-modified into circular columns with four pieces of segmental circular concrete covers and confined with three layers of CFRP. The nominal compressive strength of the segmental concrete covers was 40 MPa and 80 MPa. All columns were tested under concentric load, 25 mm or 50 mm eccentric …
Behavior Of Hybrid Frp-Concrete-Steel Double-Skin Tubular Columns With A Square Outer Tube And A Circular Innert Tube Subjected To Axial Compression, Tao Yu, J G. Teng
Behavior Of Hybrid Frp-Concrete-Steel Double-Skin Tubular Columns With A Square Outer Tube And A Circular Innert Tube Subjected To Axial Compression, Tao Yu, J G. Teng
Faculty of Engineering and Information Sciences - Papers: Part A
Hybrid fiber-reinforced polymer (FRP) concrete steel, double skin tubular columns (DSTCs) are a new form of hybrid columns. The most common sectional form of hybrid DSTCs consists of a layer of concrete sandwiched between a circular inner steel tube and a circular outer FRP tube whose fiber directions are close to the hoop detection to provide effective confinement to the concrete. Much recent research has been conducted on circular hybrid DSTCs, which has demonstrated that the combination of the three constituent materials leads to several advantages not available with existing forms of columns. In practical applications, for aesthetic and other …
Self-Shape Optimisation Of Cold-Formed Steel Columns, Timothee Savoyat, Benoit Gilbert, Lip H. Teh
Self-Shape Optimisation Of Cold-Formed Steel Columns, Timothee Savoyat, Benoit Gilbert, Lip H. Teh
Faculty of Engineering and Information Sciences - Papers: Part A
One of the main advantages of cold-formed steel profiles is the great flexibility of cross-sectional shapes, attributable to the manufacturing process allowing achievement of almost any desired cross-section. The cross-sectional shape is the key element in enhancing the strength of coldformed steel profiles as it controls the three fundamental buckling modes: local, distortional (for open profiles) and global. However, research on optimisation of cold-formed steel profiles has been mainly restricted to the conventional C, Z or Σ cross-sectional shapes and seldom new crosssectional shapes have been considered. This report presents the optimisation of cold-formed open columns using the recently developed …
Behaviour Of Cfrp Wrapped Square Rc Columns Under Eccentric Loading, Xu Lei, Thong Minh Pham, Muhammad N. Hadi
Behaviour Of Cfrp Wrapped Square Rc Columns Under Eccentric Loading, Xu Lei, Thong Minh Pham, Muhammad N. Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
Fibre Reinforced Polymer (FRP) is an excellent material to strengthen existing structures. However, the confinement efficiency of FRP - confined square columns is relatively low compared to circular columns due to stress concentration at the sharp corners. This paper presents a new techniqu e aimed to maximise the efficiency of FRP confinement for square concrete columns : circularisation using segmental circular concrete covers . Sixteen square reinforced concrete columns were cast. Four were used as a reference group; four were rounded 20 mm at each corner and wrapped with three layers of CFRP simulating the conventional methods; the rest eight …
Nonlinear Analysis Of Biaxially Loaded High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Part I: Theory, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, Muhammad N. S Hadi
Nonlinear Analysis Of Biaxially Loaded High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Part I: Theory, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a new numerical model for the nonlinear inelastic analysis of biaxially loaded high strength thin-walled rectangular concrete-filled steel tubular (CFST) slender beam-columns. The numerical model considers the effects of progressive local buckling, initial geometric imperfections, high strength materials and second order. The accurate fiber element method is used to model the inelastic behavior of composite cross-sections. Theoretical models are developed that simulate the load-deflection responses and strength envelopes of thin-walled rectangular CFST slender beamcolumns under biaxial loads. New computational algorithms based on the M ller's method are developed to adjust the depth and orientation of the neutral …
Hybrid Frp-Concrete-Steel Double-Skin Tubular Columns: Cyclic Axial Compression Tests, Tao Yu, Yu-Bo Cao, Bing Zhang, J G. Teng
Hybrid Frp-Concrete-Steel Double-Skin Tubular Columns: Cyclic Axial Compression Tests, Tao Yu, Yu-Bo Cao, Bing Zhang, J G. Teng
Faculty of Engineering and Information Sciences - Papers: Part A
Hybrid FRP-concrete-steel double-skin tubular columns (hybrid DSTCs) are a new form of hybrid columns recently developed at The Hong Kong Polytechnic University. A hybrid DSTC consists of an inner steel tube, an outer FRP tube and a concrete infill between the two tubes. Hybrid DSTCs possess many important advantages over existing column forms, including their excellent corrosion resistance and excellent seismic resistance. While a large amount of research has been conducted on the monotonic behavior of this novel form of columns, only a limited amount of work has been conducted on their behavior under cyclic loading. This paper presents the …
Behaviour Of Hybrid Double-Skin Tubular Columns Subjected To Combined Axial Compression And Cyclic Lateral Loading, Bing Zhang, J G. Teng, Tao Yu
Behaviour Of Hybrid Double-Skin Tubular Columns Subjected To Combined Axial Compression And Cyclic Lateral Loading, Bing Zhang, J G. Teng, Tao Yu
Faculty of Engineering and Information Sciences - Papers: Part A
Hybrid FRP-concrete-steel double-skin tubular columns (hybrid DSTCs) are a new form of hybrid columns developed at The Hong Kong Polytechnic University. They consist of an outer tube made of fibre reinforced polymer (FRP) and an inner tube made of steel, with the space between filled with concrete. In these hybrid DSTCs, the three constituent materials are optimally combined to achieve several advantages not available with existing forms of columns, including their superior corrosion and seismic performance. This paper presents the test results of a series of large-scale hybrid DSTCs subjected to combined axial and cyclic lateral loads, with an emphasis …
Non-Uniform Stress Distribution In Frp-Wrapped Circular Concrete Columns Under Uniform Axial Deformation, S Q. Li, J F. Chen, Tao Yu, J G. Teng
Non-Uniform Stress Distribution In Frp-Wrapped Circular Concrete Columns Under Uniform Axial Deformation, S Q. Li, J F. Chen, Tao Yu, J G. Teng
Faculty of Engineering and Information Sciences - Papers: Part A
The confinement of concrete columns using bonded FRP wraps has become a popular retrofit technique. Through extensive research in the last two decades, many stress-strain models have been developed for concrete in FRP-wrapped circular columns. All these models assume that the stress state is axisymmetric in an FRP-wrapped circular concrete column under concentric axial compression. This implies that the FRP wrap is assumed to be axisymmetric in geometry, but in reality such axisymmetry is not realised due to the existence of an overlapping zone. This paper presents a finite element investigation into the stress state in FRP-wrapped circular concrete columns …
Nonlinear Inelastic Behavior Of Circular Concrete-Filled Steel Tubular Slender Beam-Columns With Preload Effects, Vipulkumar Ishvarbhai Patel, Qing Quan Liang, Muhammad N. Hadi
Nonlinear Inelastic Behavior Of Circular Concrete-Filled Steel Tubular Slender Beam-Columns With Preload Effects, Vipulkumar Ishvarbhai Patel, Qing Quan Liang, Muhammad N. Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a numerical model based on fiber element formulations for simulating the nonlinear inelastic behavior of eccentrically loaded circular concrete-filled steel tubular (CFST) slender beam-columns with preload effects. Deflections caused by preloads are included in the global analysis of CFST slender beam-columns as initial geometric imperfections. Computational algorithms based on the Müller's method are developed to obtain load-deflection responses of CFST slender beam-columns including preload effects. The accuracy of the numerical model is examined by comparisons of computer solutions with experimental results. The numerical model is utilized to investigate the effects of preloads on the axial load-deflection curves, …