ORCID Profile
0000-0001-5499-3181
Current Organisations
Monash University
,
Curtin University
,
Victoria University
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Publisher: MDPI AG
Date: 27-06-2023
DOI: 10.3390/BUILDINGS13071634
Abstract: At present, there is a lack of research on the influence of different dynamic constitutive models of steel and concrete on the dynamic mechanical properties of concrete-filled steel tubular (CFST) columns under lateral impact. In this paper, A comprehensive numerical study on the effects of different dynamic constitutive models of steel and concrete on the lateral impact response of CFST columns was conducted. The dynamic constitutive models of steel and concrete with different strengths were ided into four categories, namely, normal-strength steel, high-strength steel, normal-strength concrete and high-strength concrete. The established finite element model of CFST columns considering the progressive damage degradation of steel as well as the compressive and tensile damage factors of concrete was verified against published experimental data. Based on the verified FE model, the effects of different dynamic constitutive models of steel and concrete on the impact response of circular CFST columns were analyzed. The analyzed results show that the different dynamic constitutive models of steel have different effects on the impact force and mid-span time-history deflection curves of CFST columns. The analysis result, ignoring the effect of concrete strain rate, is in good agreement with the CEB-FIP model considering the effect of steel strain rate. This is because the largest proportion of the impact energy of CFST members is mainly assimilated by the outer steel tube.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 03-2020
Publisher: Wiley
Date: 18-09-2002
DOI: 10.1002/POLA.10479
Publisher: Wiley
Date: 08-04-2004
DOI: 10.1002/POLA.20119
Publisher: Elsevier BV
Date: 11-2022
Publisher: Wiley
Date: 27-01-2005
DOI: 10.1002/APP.21394
Publisher: Elsevier BV
Date: 2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2007
DOI: 10.1039/B618325E
Publisher: Elsevier BV
Date: 02-2021
Publisher: Wiley
Date: 18-08-2023
Abstract: This paper investigates the shear strengthening of reinforced concrete (RC) beams incorporating engineered cementitious composite (ECC) and stainless steel plates (SSPs). The use of ECC, characterized by strain‐hardening in conjunction with SSPs, was investigated in this study to improve the shear performance of RC beams. Total 10 RC beams were tested under static loading up to failure to investigate a few key parameters, namely: material of strengthening (ECC and SSPs), the thickness of ECC, and shape and configuration of SSPs. Experimental findings showed that the proposed strengthening methods can significantly improve the failure pattern and increase the ultimate shear capacity of the studied RC beams by 36%–97% compared to the unstrengthened beam. Experimental results were compared against the predicted ultimate shear strength of RC beams using design equations specified by various design codes. Nonlinear three‐dimensional finite element modeling was developed for beams strengthened with ECC layer and validated against the test results and found to be accurate. Based on the experimental and numerical results, new shear capacity formulae were proposed considering the ratio of ECC‐to‐concrete beam cross‐section ( ρ ECC ) and then verified against the numerical predictions.
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 10-2019
Publisher: Elsevier BV
Date: 2023
Publisher: Elsevier BV
Date: 12-2023
Publisher: Wiley
Date: 18-01-2022
Abstract: This article presents experimental and numerical studies on the axial compressive behavior of square concrete‐encased concrete‐filled steel tubular (CECFST) short columns composed of a circular inner steel tube. Tests on six full‐scale short CECFST columns with the inner circular tube diameter varying from 320 to 500 mm were carried out to study the influences of sectional diameter and the tube thickness of circular CFST columns on their axial performance. A theoretical model is developed using fiber analysis method and validated against a large test database. The accuracy of various codified design models is evaluated and a simple model is proposed to calculate their ultimate strengths. Test results show that CECFST columns have improved load carrying capacity and can sustain large axial loads without significant strength degradation. In addition, increasing the thickness of the steel tube significantly improves the composite action of the steel and concrete of the inner CFST column, which increases the compressive strength of CECFST columns by 27.3%. However, the rate of increase in the compressive strength of the core concrete of the CFST column has been found to be higher for the column with a smaller local slenderness ratio. The ductility of CECFST columns is influenced by the concrete strength and the spacing of the stirrups. Furthermore, the design model suggested in this study can provide a better estimation than the codified design models.
Publisher: SAGE Publications
Date: 10-01-2022
DOI: 10.1177/13694332211065187
Abstract: Circular concrete-filled double-skin steel tubular (CFDST) columns with external stainless-steel are high-performance composite columns that have potential applications in civil construction including the construction of offshore structures, bridge piers, and transmission towers. Reflecting the limited research performed on investigating their mechanical performance, this study develops a computationally efficient fiber model to simulate the responses of short and slender beam-columns accounting for the influences of material and geometric nonlinearities. Accurate material laws of stainless steel, carbon steel, and confined concrete are implemented in the mathematical modeling scheme developed. A new solution algorithm based on the Regula-Falsi method is developed to maintain the equilibrium condition. The independent test results of short and slender CFDST beam-column are utilized to validate the accuracy of the theoretical solutions. The influences of various column parameters are studied on the load-axial strain [Formula: see text] curves, load-lateral deflection [Formula: see text] curves, column strength curves, and interaction curves of CFDST columns. Design formulas are suggested for designing short and beam-columns and validated against the numerical results. The computational model is found to be capable of simulating the responses of CFDST short and slender columns reasonably well. Parametric studies show that the consideration of the concrete confinement is important for the accuracy of the prediction of their mechanical responses. Furthermore, high-strength concrete can be utilized to enhance their load-carrying capacity particularly for short and intermediate slender beam-columns. The strengths of CFDST columns computed by the suggested design model are in good agreement with the test and numerical results.
Publisher: SAGE Publications
Date: 19-10-2021
DOI: 10.1177/13694332211046345
Abstract: This article investigates the axial compressive performance of concrete-filled double steel tubular (CFDST) short columns composed of circular section loaded concentrically. An experimental program comprised of compression tests on short columns is carried out to examine their structural performance. Axial compression tests on conventional concrete-filled steel tubular (CFST) columns and double-skin concrete-filled steel tubular (DCFST) columns are also performed for comparison purposes. The test parameters include the diameter-to-thickness of the outer and inner steel tubes, concrete strength, and diameter ratio. The test results exhibit that CFDST short columns composed of the circular section have improved structural performance compared to its CFST and DCFST counterparts. A theoretical model is also presented to simulate the test ultimate strengths and load-axial strain relationships of CFDST columns. The existing design models proposed including the codified design specifications are evaluated against the collected test data for predicting the axial compressive strengths of circular CFDST columns. It is seen that the existing codified design models cannot yield their ultimate axial compressive strengths accurately. A practical artificial neural network (ANN) model is proposed to estimate the ultimate load of such columns loaded concentrically.
Publisher: Wiley
Date: 18-05-2004
DOI: 10.1002/APP.20627
Publisher: Informa UK Limited
Date: 03-07-2017
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 10-2020
Publisher: Wiley
Date: 08-03-2004
DOI: 10.1002/APP.20233
Publisher: SAGE Publications
Date: 22-03-2021
DOI: 10.1177/13694332211004111
Abstract: In this paper, the structural behavior of concrete-filled double steel tubular (CFDST) stub columns composed of square hollow sections is investigated experimentally and numerically. The experimental program comprises compression tests on short columns loaded concentrically. The test parameters mainly focused on the influences of the width-to-thickness ratios of steel tubes and concrete strength on the axial behavior of CFDST stub columns. Finite element (FE) models are also developed to investigate the influences of a wide range of structural parameters on their axial performance. It is observed that square CFDST columns have improved strength and ductility compared to their CFST and DCFST counterparts. Finally, a calculation formula is proposed to predict their ultimate compressive strengths under the axial compression load.
Publisher: Elsevier BV
Date: 09-2023
Publisher: Elsevier BV
Date: 2022
Publisher: Wiley
Date: 08-03-2004
DOI: 10.1002/PI.1210
Publisher: Wiley
Date: 14-12-2005
DOI: 10.1002/POLA.20533
Publisher: Elsevier BV
Date: 10-2019
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 11-2018
Publisher: Elsevier BV
Date: 02-2004
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 11-2023
Publisher: SAGE Publications
Date: 19-07-2021
DOI: 10.1177/13694332211033964
Abstract: The behavior of fiber-reinforced polymer (FRP)–confined recycled aggregate concrete-filled steel tube (RACFT) columns is barely studied. Especially, that of slender specimens has not been investigated so far. In this article, an experimental test of FRP-confined RACFT slender square columns was conducted to study the influences of recycled aggregate (RA) replacement ratios, FRP thicknesses, and wrapping schemes on their axial behavior. Results in this article suggest that the RA replacement ratio barely affects the initial stiffness of load-deflection curves of specimens. Moreover, the specimen with a higher RA replacement ratio has a lower axial stress but larger strain at the peak point. The external FRP jackets (either partial or full wrap) can effectively improve the performance of axially loaded RACFT columns, and the improvement of ductility due to the increase of the FRP thickness is more significant than that of axial compressive strength. Additionally, it was found that the axial strength and ultimate axial strain decrease with increasing slenderness ratios. Furthermore, the influences of slenderness ratios on the behavior of such columns are more significant for the column with a larger length-to-width ratio. Finally, a design model for FRP-confined RACFT slender square columns is developed, which can predict the results of the present test accurately.
Publisher: Elsevier BV
Date: 2023
Publisher: Elsevier BV
Date: 11-2020
Publisher: SAGE Publications
Date: 05-07-2022
DOI: 10.1177/13694332221113041
Abstract: A square concrete-filled double steel tubular (CFDST) column composed of a circular core concrete-filled tube offers the advantages of both square and circular concrete-filled steel tubular (CFST) columns. However, limited tests were performed to investigate the axial performance of CFDST slender columns. This paper investigates the behavior and design of square CFDST slender columns subjected to concentric loading. A total of eight columns, including six CFDST slender columns and two CFDST short columns were tested under concentric loading. The test parameter includes the slenderness ratio of the columns and the thickness of the inner tube. The ultimate load, failure modes and axial load-deflection relationships of CFDST slender columns are presented. It was observed that square CFDST slender columns failed due to the overall buckling of the columns together with the localized buckling of the steel tube and concrete crushing. Increasing the slenderness ratio and decreasing the thickness of the inner steel tube reduced the ultimate load of CFDST slender columns. The applicability of the existing design code of CFST columns in designing CFDST slender columns was evaluated. It was found that the existing design codes significantly underestimated the ultimate loads of CFDST columns.
Publisher: Elsevier BV
Date: 07-2003
Publisher: World Scientific Pub Co Pte Ltd
Date: 28-09-2023
Publisher: Wiley
Date: 22-03-2004
Publisher: Elsevier BV
Date: 12-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2006
DOI: 10.1039/B609065F
Publisher: Elsevier BV
Date: 12-2019
Publisher: SAGE Publications
Date: 29-06-2022
DOI: 10.1177/00219983221107257
Abstract: A Levi-type analytical solution procedure is developed to characterize static and dynamic deformation response of smart laminated simply-supported composite rectangular plates induced by inclined piezoelectric actuators under (1) constant electrical voltage and (2) time-dependent electrical voltage with excitation frequency. The key to development of this analytical solution is to employ higher order finite integral transform and discretized higher order partial differential unit step function equations. Unlike earlier studies, this research aims to investigate the effect of inclination angle of piezoelectric actuators on static and dynamic deformation response of laminated composite plates under both static and dynamic conditions. The developed analytical solution procedure is implemented computationally through Matlab-based computer code. Its accuracy is initially investigated through convergence study and results comparison with the published literature for a particular case when inclination angle is θ = 0°, which is only limited to bending deformation response. Since there is no published benchmark data for twisting deformation response analysis caused by inclination angle of piezoelectric actuators (θ ≠ 0°), a set of robust and realistic numerical analysis using Abaqus finite element analysis (FEA) is conducted. Good agreement between the analytical and numerical results is observed. Unlike applied electrical voltage, inclination angle of a piezoelectric actuator does not have a significant impact on twisting deformation response during static mode whereas, both the excitation frequency and inclination angle can significantly influence maximum litude of vibration.
Publisher: Wiley
Date: 12-12-2023
Abstract: This paper presents experimental and numerical investigations on circular concrete‐filled double steel tubular (CFDST) members under flexural load. Seven specimens including five CFDST specimens were tested and the test parameters included the effects of concrete compressive strength, the thickness of the steel tubes, and the diameter ratio on their flexural performance. The final failure modes, moment ( M )‐curvature ( ϕ ) curves, deflection curves of specimens, and distributions of section longitudinal strains were analyzed and reported in this study. A nonlinear finite element model (FEM) was then developed for the CFDST members. After successful validation in ultimate strengths and failure modes, parametric studies were performed by using the verified FEM. A simple formula for calculating the flexural capacity of CFDST members was proposed and compared against several design codes to investigate the design accuracy. Based on this study, it was found that the CFDST members exhibit ductile behavior under flexural load. Increasing the steel area, particularly for the outer tube improved the flexural capacities of the members. Furthermore, the existing design codes were found to be remarkably underestimating the moment capacities of CFDST members whereas the design formula proposed can predict the ultimate flexural capacity with reasonable accuracy.
Publisher: SAGE Publications
Date: 10-07-2021
DOI: 10.1177/13694332211029735
Abstract: Hexagonal concrete-filled steel tubular (HCFST) columns have been used to carry large loads in tall composite buildings. Their behavior and strength are different from those of circular and square concrete-filled steel tubular (CFST) columns due to the confinement effect. This article describes a computational modeling method of nonlinear fiber analysis recognizing the concrete confinement for the response simulation of HCFST short columns subjected to axial compression. New constitutive relations of confinement for quantifying the confining stresses on the concrete confined by the hexagonal steel tube and the residual concrete strength are developed by means of analyzing existing test data. The computational modeling program written is verified by existing experimental data and then employed to ascertain the behavior of HCFST columns with important parameters. The current design standards for CFST circular columns are used to determine the strengths of HCFST columns to evaluate their applicability to the design of HCFST columns. Proposed is a new simple design equation for computing the axial capacities of HCFST columns. The computational model and the design equation proposed are shown to be accurate, and effective simulation and design tools for HCSFT stub columns that are loaded concentrically in comparisons with the current design codes.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 12-2021
No related grants have been discovered for Mizan Ahmed.