Influence of Shear Connector Size on Ultimate Strength in Composite Construction with Cold-Formed Steel Channel Lipped Section

2016 ◽  
Vol 3 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Mahmood Md Tahir ◽  
Mustapha Muhammad Lawan ◽  
Anis Saggaff ◽  
Jahangir Mirza
2016 ◽  
Vol 78 (6-12) ◽  
Author(s):  
Mustapha Muhammad Lawan ◽  
Mahmood Md. Tahir ◽  
Emad Hosseinpour

In conventional composite construction for hot-rolled steel (HRS) section, the composite action is usually achieved by using headed studs shear connectors. But, for cold-formed steel (CFS) section, the use of headed studs is not feasible as the section is very thin and difficult to be weld.  Therefore, an innovative way of shear connection mechanism of using bolt and nut is suggested in this study. This paper presents the feasibility of using bolt as shear connector by presenting experimental test results so as to explore more on their capability to be used as shear connectors. The study investigated the structural capability of the proposed bolted shear connector when used in concrete known as Self-compacting concrete (SCC) integrated with CFS to provide the required composite action. Push out test specimens with bolted shear connector of grade 8.8 at designated intervals longitudinally spaced were fabricated, cast and tested to failure. The results showed that the proposed shear connector was structurally capable and also an appreciable strength resistance was achieved. 


2015 ◽  
Vol 77 (16) ◽  
Author(s):  
Mustapha Muhammad Lawan ◽  
Mahmood Md. Tahir ◽  
Mohd. Hanim Osman

Composite construction is well known to be effectively used in the construction of buildings and bridges using hot rolled steel (HRS) and headed studs connectors. The shear connectors provides the enhancement as established in current design codes. In this paper, the shear connection mechanism was proposed using high strength bolted shear connector to provide composite action between concrete and the steel section. The conventional headed stud shear connector was eliminated since Cold-formed steel (CFS) was used and welding was not practically possible due to thinness nature of the CFS section. Therefore, in this study investigation was carried out on the strength capacity, ductility and the ultimate flexural capacity of the proposed high strength bolted shear connector and the composite beam specimens respectively. Four push-out and two full-scale composite beam specimens were fabricated using high strength M16 bolted shear connector of Grade 8.8 connected to the top flanges of the CFS I-section and tested to failure using push-out and four-point bending tests respectively. The results show that ultimate load and ultimate moment capacities of the proposed system were significantly improved by using the proposed connectors. The experimental results were compared with theoretical results based on the provision of Eurocode 4, and good agreement between the results was observed. In conclusion, compared results proved that the ultimate moment capacity of the proposed composite beams can be estimated efficiently by using the constitutive laws as prescribed by Eurocodes and British standards.


2017 ◽  
Vol 11 (1) ◽  
pp. 244-257 ◽  
Author(s):  
Xingyou Yao

Background: Cold-formed steel structural sections used in the walls of residential buildings and agricultural facilities are commonly C-shaped sections with web holes. These holes located in the web of sections can alter the elastic stiffness and the ultimate strength of a structural member. The objective of this paper is to study the buckling mode and load-carrying capacity of cold-formed thin-walled steel column with slotted web holes. Methods: Compression tests were conducted on 26 intermediate length columns with and without holes. The tested compressive members included four different kinds of holes. For each specimen, a shell finite element Eigen-buckling analysis and nonlinear analysis were also conducted. The influence of the slotted web hole on local and distortional buckling response had also been studied. The comparison on ultimate strength between test results and calculated results using Chinese cold-formed steel specification GB50018-2002, North American cold-formed steel specification AISI S100-2016, and nonlinear Finite Element method was made. Result: Test results showed that the distortional buckling occurred for intermediate columns with slotted holes and the ultimate strength of columns with holes was less than that of columns without holes. The ultimate strength of columns decreased with the increase in transverse width of hole in the cross-section of member. The Finite element analysis results showed that the web holes could influence on the elastic buckling stress of columns. The shell finite element could be used to model the buckling modes and analysis the ultimate strength of members with slotted web holes. The calculated ultimate strength shows that results predicted with AISI S100-2016 and analyzed using finite element method are close to test results. The calculated results using Chinese code are higher than the test results because Chinese code has no provision to calculate the ultimate strength of members with slotted web holes. Conclusion: The calculated method for cold-formed thin-walled steel columns with slotted web holes are proposed based on effective width method in Chinese code. The results calculated using the proposed method show good agreement with test results and can be used in engineering design for some specific cold-formed steel columns with slotted web holes studied in this paper.


2018 ◽  
Vol 22 (3) ◽  
pp. 613-625 ◽  
Author(s):  
M Anbarasu ◽  
M Venkatesan

This work reports numerical results concerning the cold-formed steel built-up I-section columns composed of four U-profiles under axial compression. A finite element model is developed by using the software program ABAQUS. The developed model includes geometric, material nonlinearities and geometric imperfections. The finite element model was verified against the experimental results reported in the cold-formed steel built-up open section columns. In the parametric study, the sections are analysed with several cross-sectional dimension ratios and lengths, in order to assess their influence on the buckling behaviour and ultimate strength of cold-formed steel built-up I-section columns. After presenting and discussing the numerical parametric results, the article shows that the current direct strength method in the North American Specification for cold-formed steel compression members design curve fails to predict adequately the ultimate strength of some of the columns analysed and addresses the modification proposed on current direct strength method curves, providing improved predictions of all the numerical ultimate strength available. The proposed method is also assessed by reliability analysis.


2016 ◽  
Vol 13 (10) ◽  
pp. 6892-6895
Author(s):  
J Thivya ◽  
R Malathy ◽  
D Tensing

This study concerns the employment of pure torsion analysis to determine ultimate strength of composite beam with shear connectors. The effect of shear connector is used for increasing the strength and stiffness of composite beam. This behavior is influenced by physical response of the beam under pure torsion. Totally 12 beams are tested and comparative analysis has been made within this 12 beams. The curvature, rotation and angle of twist are calculated throughout entire load by torsion test. This investigation proves that the composite beam with 75 mm spaced shear connector provides good ultimate strength.


2020 ◽  
Vol 9 (2) ◽  
pp. 1033-1043

This research mainly concentrates on ultimate strength and buckling behaviour of cold formed steel (CFS) laterally un-braced longitudinally stiffened box sections under flexure. A total of five various stiffener combinations for box sections has been studied by modifying the shape of a simple end stiffened section by the provision of intermediate stiffeners along web, flange or both along web and flange. The influence of different types of stiffeners with respect to various aspect radio’s (H/T, B/T, C/T and H/B) have been studied using Finite Element Method (FEM), and recommendations have been proposed on provisions of different stiffener’s combinations. This study mainly details with ultimate strength and buckling behaviour of CFS laterally unbraced stiffened box sections made by C sections connected face to face.


2018 ◽  
Vol 7 (3.9) ◽  
pp. 38 ◽  
Author(s):  
M M. Lawan ◽  
P N. Shek ◽  
M M. Tahir

For decades, Hot Rolled Steel (HRS) section was in use in construction of buildings and bridges. The simple reason is that the use of HRS section in composite systems is well established by standard rules and their design necessities as provided in the codes. In this paper, the use of doubly oriented back-to-back Cold-Formed Steel (CFS) section coupled with bolted shear connectors in composite floor system was demonstrated. The bolted system of shear connector provides an alternative to headed stud shear connector with CFS section as welding of the stud connector is practically not feasible on CFS section because of its thinness nature. The loading system used was four-point bending test to determine the flexural strength capabilities of the composite floor system. The resulting composite floor system has proven to provide adequate strength and stiffness properties under the applied loads. The results have shown that the theoretical value of flexural capacities calculated agrees reasonably well with the experimental values. In conclusion, the composite floor system can be used in small and medium size buildings, as well as in light weight construction industries.    


Sign in / Sign up

Export Citation Format

Share Document