scholarly journals A Study on the Effect of Hollow Tubular Flange Sections on the Behavior of Cold-Formed Steel Built-Up Beams

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Balaji Shanmugam ◽  
Manikandan Palanisamy ◽  
Paul O. Awoyera ◽  
Senthilnathan Chinnasamy ◽  
Mahalakshmi Subramaniam
Keyword(s):  
Flexural Strength ◽  
Failure Modes ◽  
Flexural Behavior ◽  
Test Results ◽  
Structural Members ◽  
Iron And Steel ◽  
Loading System ◽  
Failure Loads ◽  
Cold Formed Steel ◽  
The Web

This paper deals with a study conducted on flexural behavior of cold-formed steel built-up I-beams with hollow tubular flange sections. There were two types of test sections, namely, built-up sections that were assembled with either stiffened or unstiffened channels coupling back-to-back at the web and a hollow tubular rectangular flange at the top and bottom of the web to form built-up I-beam. The flexural behavior along with the strength and failure modes of the built-up sections was examined using the four-point loading system. Nonlinear finite element (FE) models were formulated and validated with the experimental test results. It was observed that the developed FE models had precisely predicted the behavior of built-up I-beams. Further, the verified FE models were used to conduct a detailed parametric study on cold-formed steel built-up beam sections with respect to thickness, depth, and yield stress of the material. The flexural strength of the beams was designed using the direct strength method as specified in American Iron and Steel Institute (AISI) for the design of cold-formed steel structural members and was compared with the experimental results and the failure loads predicted from FE models. Since the results were not conservative, a new customized design equation had been mooted and delineated in the study for determining the flexural strength of cold-formed steel built-up beams with hollow tubular flange sections.

scholarly journals Glulam beams: Performance of PVA and PUR adhesives on bending strengths of locally selected Nigerian timber species

2021 ◽  
Vol 40 (3) ◽  
pp. 363-370
Author(s):  
C. Arum ◽  
I.O. Olofintuyi ◽  
O.O. Ekundayo
Keyword(s):  
Flexural Strength ◽  
Timber Species ◽  
Structural Members ◽  
Gmelina Arborea ◽  
Structural Applications ◽  
Different Types ◽  
Loading System ◽  
Failure Loads ◽  
Bending Loads ◽  
Continuous Use

The applicability of structural timber to construction is due to its desirable qualities such as lightweight, aesthetics and eco-friendliness. However, continuous use of timber for structural purposes comes with the challenge posed by the anisotropic nature of various timber species. Advanced societies have developed and modified their sawn timber species in form of glue-laminated structural members such as beams, columns, joist etc. Nigeria timber species are yet to be fully explored along glued-laminated beams production. This paper assesses the suitability of three selected Nigerian timber species namely; Gmelina Arborea (ML), Terminalia superba (AF) and Pycnanthus angolensis (AK) for production of glued-laminated (glulam) beams. They are locally known respectively as Melina (ML), Afara (AF) and Akomu (AK). The applicability and glue-ability of the glues and their ultimate effect on the flexural strength were investigated through the use of two different types of glue components namely; polyvinyl acetate (PVA) and polyurethane (PUR) glue. The physical properties of the timber species such as moisture content (MC) and densities were determined using BS EN 408. The beams produced which are 1680mm by 150mm by 120mm in dimension were subjected to two points loading system to determine their flexural strengths and failure loads in accordance with ASTM D-198. The flexural strengths results indicated that Pycnanthus angolensis offered most resistance to bending loads with an average flexural strength value of 16.04N/mm2 when PUR glue was used and 13.04N/mm2 when PVA glue was used. The ANOVA result showed that glue types have significant effect on the flexural strength at confidence level of 95%. It was concluded that Pycnanthus angolensis is most suitable for structural applications. PUR is considered the better glue in terms of strength and glue-ability while PVA glue is considered better in terms of workability and applicability based on almost perfect glue line integrity achieved.

Local buckling capacity of C-shaped cold-formed steel sections with punched webs

1984 ◽  
Vol 11 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Robert Loov
Keyword(s):  
Local Buckling ◽  
Effective Width ◽  
Test Results ◽  
Average Yield ◽  
Steel Sections ◽  
Load Tests ◽  
Cold Formed Steel ◽  
Stub Column ◽  
Best Fit ◽  
The Web

Load tests were carried out on 36 stub column samples of cold-formed steel studs having 38.1 mm wide × 44.5 mm long holes punched through their webs, steel thicknesses of 1.21–2.01 mm, and overall section depths of 63–204 mm. Based on these tests a best-fit equation for the effective width of the unstiffened portion of the web beside the holes has been developed. Suggested design equations have been proposed. The test results support the present equation for the average yield stress [Formula: see text] in Canadian Standards Association Standard S136-1974 but the present code equations for unstiffened plates are unduly conservative when applied to the design of the web adjacent to openings of the size considered.

scholarly journals Compression Test on Cold-Formed Steel Built-Up Back-to-Back Channels Stub Columns

2011 ◽  
Vol 201-203 ◽  
pp. 2900-2903 ◽  
Author(s):  
Chui Huon Tina Ting ◽  
Hieng Ho Lau
Keyword(s):  
Compression Test ◽  
Failure Modes ◽  
Local Buckling ◽  
Effective Width ◽  
Test Results ◽  
Direct Strength Method ◽  
Cold Formed Steel ◽  
Stub Column ◽  
Hot Rolled ◽  
Stub Columns

Built-up sections are used to resist load induced in a structure when a single section is not sufficient to carry the design load for example roof trusses. In current North American Specification, the provision has been substantially taken from research in hot-rolled built-up members connected with bolts or welds [1]. The aim of this paper is to investigate on built-up back-to-back channels stub columns experimentally and theoretically using Effective Width Method and Direct Strength Method. Compression test was performed on 5 lipped channel and 5 back-to-back channels stub columns fabricated from cold-formed steel sheets of 1.2mm thicknesses. The test results indicated that local buckling is the dominant failure modes of stub columns. Therefore, Effective Width Method predicts the capacity of stub columns compared to Direct Strength Method. When compared to the average test results, results based on EWM are 5% higher while results based on DSM are 12% higher for stub column.

scholarly journals Experiment and Design Method on Cold-Formed Thin-Walled Steel Lipped Channel Columns with Slotted Web Holes Under Axial Compression

2017 ◽  
Vol 11 (1) ◽  
pp. 244-257 ◽  
Author(s):  
Xingyou Yao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Ultimate Strength ◽  
Test Results ◽  
Distortional Buckling ◽  
Steel Columns ◽  
Cold Formed Steel ◽  
Thin Walled ◽  
Shell Finite Element ◽  
The Web

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.

scholarly journals Flexure Performance of Externally Bonded CFRP Plates-Strengthened Reinforced Concrete Members

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xin Yuan ◽  
Chaoyu Zhu ◽  
Wei Zheng ◽  
Jiangbei Hu ◽  
Baijian Tang
Keyword(s):  
Failure Modes ◽  
Calculation Model ◽  
Flexural Behavior ◽  
Test Results ◽  
Flexural Test ◽  
Concrete Members ◽  
Cfrp Plate ◽  
Matlab Program ◽  
Externally Bonded ◽  
The Relationship

This paper investigates the flexural behavior of CFRP plate-strengthened concrete structures. Specimens of the CFRP plate-reinforced beam were designed and tested by the four-point flexural test. The load-deflection relationship, failure modes, and crack propagation were analyzed. The results showed that the postcracking stiffness and bearing capacity of the test beams can be improved by the additional anchoring measures for CFRP strengthening. The relationship between flexural moment and curvature was analyzed by introducing a MATLAB program. The calculation model between curvature, flexural moment, and stiffness was derived for the CFRP plate-strengthened structure. The recommended calculation model was applied in the analysis of deflection, and the theoretical values were compared with the test results.

Simplified calculation method for flexural moment capacity of cold-formed steel built-up section beams

2020 ◽  
Vol 23 (14) ◽  
pp. 3153-3167
Author(s):  
Xinmei Yao ◽  
Xuhong Zhou ◽  
Yu Shi ◽  
Yu Guan ◽  
Yuxuan Zou
Keyword(s):  
Calculation Method ◽  
Flexural Behavior ◽  
Moment Capacity ◽  
Failure Characteristics ◽  
Box Section ◽  
Cold Formed Steel ◽  
The Moment ◽  
Simplified Calculation ◽  
The Web ◽  
Simplified Calculation Method

Cold-formed steel built-up section beams are commonly employed in cold-formed steel framing owing to their excellent mechanical performance. In order to develop a simplified approach for obtaining the flexural moment capacity of built-up section beams, both experimental study and numerical analysis on the flexural behavior of cold-formed steel built-up I-section and box section beams under flexural load were carried out in this study. The I-section beams are assembled from two back-to-back cold-formed steel lipped channels, and the box section beams consist of a cold-formed steel plain channel overlapping a lipped channel. First, four-point bending tests were performed on 30 simply supported specimens having 10 different configurations, and the moment capacities and failure modes of built-up section beams at ultimate loads were investigated. The failure characteristics observed were the interaction of local and distortional buckling of the web and top flange for I-section beams and local buckling of the web and top flange in pure bending for box section beams. Then, finite element models were developed to simulate the tested specimens and validated against the experimental results in terms of the moment capacities and failure characteristics. Moreover, extensive parametric studies, including section height-to-width ratio and flange width-to-thickness ratio, were conducted with the validated numerical models to identify the key factors influencing built-up section beams. Finally, a simplified calculation method considering the reduction factor of the gross section modulus of the built-up section to predict the flexural moment capacities of cold-formed steel built-up I-section and box section beams was proposed.

Influence of Screw Spacing on the Strength of Self-Drilling Screw Connection for the High Strength Cold-Formed Steel

2013 ◽  
Vol 712-715 ◽  
pp. 1054-1057 ◽  
Author(s):  
Siti Fairuz Sapiee ◽  
Hieng Ho Lau
Keyword(s):  
Failure Modes ◽  
High Strength ◽  
Connection Strength ◽  
Iron And Steel ◽  
Steel Construction ◽  
Steel Members ◽  
Primary Means ◽  
Cold Formed Steel ◽  
Connection Design ◽  
Single Shear

Self-drilling screws are the primary means of fastening for cold-formed steel members in cold-formed thin-gauge steel residential construction because it can drill their own holes and form their own threads. The fabrication of connections is the most labour intensive aspect of the cold-formed thin-gauge steel construction process, thus a better understanding of the behaviour of screw connections could lead to optimum connection design and reducing the cost of the fabrication. The study carried out to investigate the behaviour of single-shear connections using self-drilling screws in the cold-formed steel construction. The focus of this study is on the influence of the number of screws and screw spacing on the strength of self-drilling screw connection. These parameters are varied to determine their influences on the connection strength. The failure load and failure modes were obtained and observed from the tests carried out in the laboratory. Bearing and tilting failures occurred during the testing of these specimens. The predicted connection strengths were calculated using American Iron and Steel Institute (AISI) design equations. A total of 24 specimens of single shear test showed that connection strength is linearly proportional to the number of screw in the connection. Results of the specimen with spacing more than 3d show better correlation with the calculated results as compared to specimens with screw spacing less than 3d.

Analysis of Cold-Formed Steel Lipped Channel Columns with Complex Edge Stiffeners and Web Holes

2013 ◽  
Vol 405-408 ◽  
pp. 664-667
Author(s):  
Chun Gang Wang ◽  
Yu Fei Cao ◽  
Lian Guang Jia ◽  
Hong Liu
Keyword(s):  
Finite Element Analysis ◽  
Failure Modes ◽  
Ultimate Load ◽  
Width Ratio ◽  
Distortional Buckling ◽  
Element Analysis ◽  
Stress Changes ◽  
Cold Formed Steel ◽  
The Web ◽  
Steel Section

This paper presents finite element analysis on cold-formed steel-section columns with complex edge stiffeners and web holes under axial compression. A total of 18 channel models with different parameters such as length, thickness and flange width are simulated. Failure modes, the ultimate load and the stress distribution around web holes are researched. The analysis results show that, the main failure mode of-section columns with complex edge stiffeners and web holes is distortional buckling. The carrying efficiency is higher as the thickness-width ratio increasing. Because of perforations on the web, the position of the max stress changes from the web near the mid-height of the specimens to the location adjacent to holes.

scholarly journals Experimental and Numerical Investigation of a Method for Strengthening Cold-Formed Steel Profiles in Bending

2020 ◽  
Vol 10 (11) ◽  
pp. 3855 ◽  
Author(s):  
Ehsan Taheri ◽  
Ahmad Firouzianhaji ◽  
Peyman Mehrabi ◽  
Bahador Vosough Hosseini ◽  
Bijan Samali
Keyword(s):  
Cost Effective ◽  
Major Axis ◽  
Flexural Behavior ◽  
Test Results ◽  
Buckling Modes ◽  
Flexural Performance ◽  
Cost Effective Method ◽  
Bending Capacity ◽  
Cold Formed Steel ◽  
The Cost

Perforated cold-formed steel (CFS) beams subjected to different bending scenarios should be able to deal with different buckling modes. There is almost no simple way to address this significant concern. This paper investigates the bending capacity and flexural behavior of a novel-designed system using bolt and nut reinforcing system through both experimental and numerical approaches. For the experiential program, a total of eighteen specimens of three types were manufactured: a non-reinforced section, and two sections reinforced along the upright length at 200 mm and 300 mm pitches. Then, monotonic loading was applied to both the minor and major axes of the specimens. The finite element models were also generated and proved the accuracy of the test results. Using the proposed reinforcing system the flexural capacity of the upright sections was improved around either the major axis or minor axis. The 200 mm reinforcement type provided the best performance of the three types. The proposed reinforcing pattern enhanced flexural behavior and constrained irregular buckling and deformation. Thus, the proposed reinforcements can be a very useful and cost-effective method for strengthening all open CFS sections under flexural loading, considering the trade-off between flexural performance and the cost of using the method.

Flexural Behavior of Ferrocement Plates Incorporating Steel and PET Fibers

2015 ◽  
Vol 666 ◽  
pp. 97-106
Author(s):  
Comingstarful Marthong ◽  
Deba Kumar Sarma
Keyword(s):  
Flexural Strength ◽  
Energy Absorption ◽  
Volume Fraction ◽  
Flexural Behavior ◽  
Test Results ◽  
Slight Improvement ◽  
Variable Parameters ◽  
The Matrix ◽  
Negative Effect ◽  
Pet Fibers

Ferrocement plate with steel meshes incorporating fibers in an identical matrix were tested under bending. The main objective of the study was to investigate the effects of combining reinforcing steel meshes with discontinuous fibers as reinforcement in thin mortar matrix. The variable parameters were chosen as (a) number of mesh layers, single and double (b) the types of fiber i.e steel and polyethylene terephthalate (PET). Everything else being equal, the test results shows that addition of steel fibers to the matrix of ferrocement can effectively increase its flexural strength and energy absorption to failure. Cracking and spalling of mortar cover also significantly reduced. On the other hand, the contributions of same volume fraction of PET fibers are not significant compared to steel. However, addition of PET fibers control the early cracking of thin mortar and showed slight improvement in flexural strength and energy absorption to failure compared to control specimens. Reinforcing ferrocement plates incorporating steel or PET fibers is recommended for providing technical and economical advantages as no negative effect was observed.

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