The influence of strengthening the hollow steel tube and CFST beams using U-shaped CFRP wrapping scheme

Zand, Ahmed W. Al,Hosseinpour, Emad,Badaruzzaman, Wan Hamidon W. Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.2

This study investigated the behaviour of the simply supported hollow steel tube (HST) beams, either concrete filled or unfilled when strengthened with carbon fibre reinforced polymer (CFRP) sheets. Eight specimens with varied tubes thickness (sections classification 1 and 3) were all tested experimentally under static flexural loading, four out of eight were filled with normal concrete (CFST beams). Particularly, the partial CFRP strengthening scheme was used, which wrapped the bottom-half of the beams cross-section (U-shaped wrapping), in order to use the efficiency of high tensile strength of CFRP sheets at the tension stress only of simply supported beams. In general, the results showed that the CFRP sheets significantly improved the ultimate strength and energy absorption capacities of the CFST beams with very limited improvement on the related HST beams. For example, the load and energy absorption capacities for the CFST beams (tube section class 1) were increased about 20% and 32.6%, respectively, when partially strengthened with two CFRP layers, and these improvements had increased more (62% and 38%) for the same CFST beams using tube class 3. However, these capacities recorded no much improvement on the related unfilled HST beams when the same CFRP strengthening scheme was adopted.

Nonlinear analysis of concrete-filled steel composite columns subjected to axial loading

Alireza Bahrami,Wan Hamidon Wan Badaruzzaman,Siti Aminah Osman 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.39 No.3

This paper investigates the nonlinear analysis of concrete-filled steel composite columns subjected to axial loading to predict the ultimate load capacity and behaviour of the columns. Finite element software LUSAS is used to conduct the nonlinear analyses. The accuracy of the finite element modelling is verified by comparing the result with the corresponding experimental result reported by other researchers. Nonlinear analyses are done to study and develop different shapes and number of cold-formed steel sheeting stiffeners with various thicknesses of cold-formed steel sheets. Effects of the parameters on the ultimate axial load capacity and ductility of the concrete-filled steel composite columns are examined. Effects of variables such as concrete compressive strength f_c and cold-formed steel sheet yield stress f_yp on the ultimate axial load capacity of the columns are also investigated. The results are shown in the form of axial load-normalized axial shortening plots. It is concluded from the study that the ultimate axial load capacity and behaviour of the concrete-filled steel composite columns can be accurately predicted by the proposed finite element modelling. Results in this study demonstrate that the ultimate axial load capacity and ductility of the columns are affected with various thicknesses of steel sheets and different shapes and number of stiffeners. Also, compressive strength f_c of the concrete and yield stress f_yp of the cold-formed steel sheet influence the performance of the columns significantly.

Direct shear behavior of concrete filled hollow steel tube shear connector for slim-floor steel beams

Emad Hosseinpour,Shahrizan Baharom,Wan Hamidon W. Badaruzzaman,Mahdi Shariati,Abdolrahim Jalali 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.4

In this paper, a hollow steel tube (HST) shear connector is proposed for use in a slim-floor system. The HST welded to a perforated steel beam web and embedded in concrete slab. A total of 10 push-out tests were conducted under static loading to investigate the mechanical behavior of the proposed HST connector. The variables were the shapes (circular, square and rectangular) and sizes of hollow steel tubes, and the compressive strength of the concrete. The failure mode was recorded as: concrete slab compressive failure under the steel tube and concrete tensile splitting failure, where no failure occurred in the HST. Test results show that the square shape HST in filled via concrete strength 40 MPa carried the highest shear load value, showing three times more than the reference specimens. It also recorded less slip behavior, and less compressive failure mode in concrete underneath the square hollow connector in comparison with the circular and rectangular HST connectors in both concrete strengths. The rectangular HST shows a 20% higher shear resistance with a longer width in the load direction in comparison with that in the smaller dimension. The energy absorption capacity values showed 23% and 18% improvements with the square HST rather than a headed shear stud when embedded in concrete strengths of 25 MPa and 40 MPa, respectively. Moreover, an analytical method was proposed and predicts the shear resistance of the HST shear connectors with a standard deviation of 0.14 considering the shape and size of the connectors.

Vibration Performance of Profiled Steel Sheet Dry Board Composite Floor Panel

Ehsan Ahmed,Wan Hamidon Wan Badaruzzaman 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.1

Profiled Steel Sheet Dry Board (PSSDB) composite panel has been proven to be an effective structural system and can be exploited for a variety of structural purposes. As a flooring system, the PSSDB floor carries the out of plane bending and shear mainly in the direction of corrugation of profiled steel sheeting. For such flooring system, human induced vibrations are becoming increasingly vital serviceability and safety issues. In this paper, investigations are carried out on the vibration performances of the PSSDB floor panel. This research is focused mainly on the fundamental frequency of such floor panel. The influence of various board types, board thickness, and connectors spacing on fundamental frequency are evaluated. It was shown that for all the panels considered in this paper, the fundamental frequency was well above 8 Hz and hence, this type of composite floor panel will not be uncomfortable to the occupants of building in terms of vibration.

Experimental and numerical study on the PSSDB system as two-way floor units

Marwan S. Al-Shaikhli,Wan Hamidon Wan Badaruzzaman,Ahmed W. Al-Zand 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.42 No.1

This paper researches a lightweight composite structure referred to as the Profiled Steel Sheeting Dry Board (PSSDB). It is fundamentally produced by connecting a Profiled Steel Sheeting to Dry Board using mechanical screws. It is mainly employed as floor panels. However, almost all studies have focused on researching the one-way structural performance. Therefore, this study focuses on the bending behaviour of the two-way PSSDB floor system using both of Finite Element (FE) and Experimental analysis. Four panels were used in the experimental tests, and a mild steel plate has been applied at the bottom for two panels. For the FE process, models were created using ABAQUS software. 4 parametric studies have been utilized to understand the system’s influential elements. From the experimental tests, it was found that using Steel Plate shall optimize the two-way action of the system and depending on the type of dry board the improvement in stiffness may reach up to 38%. It was shown from the FE analysis that the dry board, profiled steel sheeting and steel plat can affect the system by up to 10 %, 17% and 3% respectively, while applying a uniform load demonstrate a better two-way action.

Flexural performance of cold-formed square CFST beams strengthened with internal stiffeners

Ahmed W. Al-Zand,W.H. Wan Badaruzzaman,Mustafa M. Ali,Qahtan A. Hasan,Marwan S. Al-Shaikhli 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.1

The tube outward local buckling of Concrete-Filled Steel Tube (CFST) beam under high compression stress is still considered a critical problem, especially for steel tubes with a slender section compared to semi-compact and compact sections. In this study, the flexural performance of stiffened slender cold-formed square tube beams filled with normal concrete was investigated. Fourteen (14) simply supported CFST specimens were tested under static bending loads, stiffened with different shapes and numbers of steel stiffeners that were provided at the inner sides of the tubes. Additional finite element (FE) CFST models were developed to further investigate the influence of using internal stiffeners with varied thickness. The results of tests and FE analyses indicated that the onset of local buckling, that occurs at the top half of the stiffened CFST beam’s cross-section at mid-span was substantially restricted to a smaller region. Generally, it was also observed that, due to increased steel area provided by the stiffeners, the bending capacity, flexural stiffness and energy absorption index of the stiffened beams were significantly improved. The average bending capacity and the initial flexural stiffness of the stiffened specimens for the various shapes, single stiffener situations have increased of about 25% and 39%, respectively. These improvements went up to 45% and 60%, for the double stiffeners situations. Moreover, the bending capacity and the flexural stiffness values obtained from the experimental tests and FE analyses validated well with the values computed from equations of the existing standards.

Equivalent Elastic Analysis of Profiled Metal Decking Using Finite Element Method

E. Ahmed,W. H. Wan Badaruzzaman 한국강구조학회 2003 韓國鋼構造學會誌 Vol.15 No.3

Structural behaviour of tapered concrete-filled steel composite (TCFSC) columns subjected to eccentric loading

Alireza Bahrami,Wan Hamidon Wan Badaruzzaman,Siti Aminah Osman 사단법인 한국계산역학회 2012 Computers and Concrete, An International Journal Vol.9 No.6

This paper deals with the structural behaviour of tapered concrete-filled steel composite (TCFSC) columns under eccentric loading. Finite element software LUSAS is used to perform the nonlinear analyses to predict the structural behaviour of the columns. Results from the finite element modelling and existing experimental test are compared to verify the accuracy of the modelling. It is demonstrated that they correlate reasonably well with each other; therefore, the proposed finite element modelling is absolutely accurate to predict the structural behaviour of the columns. Nonlinear analyses are carried out to investigate the behaviour of the columns where the main parameters are: (1) tapered angle (from 0o to 2.75o); (2) steel wall thickness (from 3 mm to 4 mm); (3) load eccentricity (15 mm and 30 mm); (4) L/H ratio (from 10.67 to 17.33); (5) concrete compressive strength (from 30 MPa to 60 MPa); (6) steel yield stress (from 250 MPa to 495 MPa). Results are depicted in the form of load versus mid-height deflection plots. Effects of various tapered angles, steel wall thicknesses, and L/H ratios on the ultimate load capacity, ductility and stiffness of the columns are studied. Effects of different load eccentricities, concrete compressive strengths and steel yield stresses on the ultimate load capacity of the columns are also examined. It is concluded from the study that the parameters considerably influence the structural behaviour of the columns.

Non-linear Analysis of Membrane Action Effect in Profiled Steel Sheeting Dry Board Flooring System

Mahmood Seraji,W. H. Wan Badaruzzaman,S.A. Osman 한국강구조학회 2014 International Journal of Steel Structures Vol.14 No.2

This study highlights the effect of membrane action in improving load carrying capacity of Profiled Steel Sheeting Dry Board(PSSDB) floor system. PSSDB system is a lightweight composite structural system composed of profiled steel sheeting anddry board, attached together by self-drilling and self-tapping screws. Many literatures have reported that restricting conventionalslabs, such as reinforced concrete slab, at the supports against translation and/or rotation while it is subjected to vertical loadingdevelops the compressive membrane action in the slab. The development of this phenomenon is considered in the PSSDBsystem with concrete infill for continuous and practical spans, with and without topping concrete. Previous authors’experimentally verified non-linear finite element model for the PSSDB floor without topping was extended to parametricallypredict the effect of different boundary conditions on the performance of the system for practical applications. It was revealedthat preventing the in-plane movement of the slab ends improves the flexural rigidities of the slab up to more than three timeswhen considering central deflection of serviceability limit state. This was observed when the deflection limit load of the fixedboth end supports model was compared to the pin-roller support model. Moreover, the topping concrete enhances theapplicability of the system in longer span and the developed compressive membrane action dramatically boosts the loadcarrying capacity of the slab with restricted translation and/or rotation of the slab ends.

The influence of strengthening the hollow steel tube and CFST beams using U-shaped CFRP wrapping scheme

Ahmed W. Al-Zand,Emad Hosseinpour,Wan Hamidon W. Badaruzzaman 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.2

This study investigated the behaviour of the simply supported hollow steel tube (HST) beams, either concrete filled or unfilled when strengthened with carbon fibre reinforced polymer (CFRP) sheets. Eight specimens with varied tubes thickness (sections classification 1 and 3) were all tested experimentally under static flexural loading, four out of eight were filled with normal concrete (CFST beams). Particularly, the partial CFRP strengthening scheme was used, which wrapped the bottom-half of the beams cross-section (U-shaped wrapping), in order to use the efficiency of high tensile strength of CFRP sheets at the tension stress only of simply supported beams. In general, the results showed that the CFRP sheets significantly improved the ultimate strength and energy absorption capacities of the CFST beams with very limited improvement on the related HST beams. For example, the load and energy absorption capacities for the CFST beams (tube section class 1) were increased about 20% and 32.6%, respectively, when partially strengthened with two CFRP layers, and these improvements had increased more (62% and 38%) for the same CFST beams using tube class 3. However, these capacities recorded no much improvement on the related unfilled HST beams when the same CFRP strengthening scheme was adopted.