Simplified analysis of cold-formed steel shear diaphragms

1979 ◽  
Vol 6 (2) ◽  
pp. 232-242
Author(s):  
S. Chockalingam ◽  
Kinh Ha ◽  
Paul Fazio

Research carried out on light-gage metal shear diaphragms clearly indicates that the shear behaviour depends mainly on the behaviour of the fasteners. There is no generally accepted theory to predict the shear stiffness and strength of diaphragms with welded connections, even though there exist some approximate methods for the case of diaphragms with mechanical fasteners. Simplified formulas are presented in this paper for calculating the shear stiffness and strength of metal shear diaphragms. The analysis is based on the observed deformation pattern of the panels and on the failure mode of the fasteners. By using the test data of the fasteners, the shear characteristics of many diaphragms are predicted and compared with the test results. It is of interest to note that the proposed formulas are suitable for diaphragms with any types of fasteners. Because of their generality and simplicity, the theory would be extremely useful for design engineers.

2016 ◽  
Vol 846 ◽  
pp. 251-257
Author(s):  
Nima Talebian ◽  
Benoit P. Gilbert ◽  
Nadia Baldassino ◽  
Hong Guan

Steel storage racks, commonly assembled from cold-formed steel profiles, are braced in the cross-aisle direction, where bracing members are typically bolted between two uprights forming an “upright frame”. Especially for high-bay racks and racks supporting the building enclosure, accurately determining the transverse shear stiffness of upright frames is essential in calculating the elastic buckling load, performing earthquake design and serviceability checks. International racking specifications recommend different approaches to evaluate the said transverse shear stiffness. The Rack Manufacturers Institute (RMI) Specification conservatively uses an analytical solution based on Timoshenko and Gere's theory while the European (EN15512) and Australian (AS4084) Specifications recommend testing to be conducted. Previous studies have shown that Finite Element Analyses (FEA), solely using beam elements, fail to reproduce experimental test results and may overestimate the transverse shear stiffness by a factor up to 25. This discrepancy is likely attributed to the local deformations occurring at the bolted joints. In this paper, a commercially used upright frame configuration has been modeled using shell elements in FEA and the response is verified against published experimental test results. A good correlation is found between the FEA and test results, concluding that shell elements are able to fully capture the behaviour of the upright frame. Future studies on the use of the FE model are also presented.


Author(s):  
Wenying Zhang ◽  
Yuanqi Li ◽  
Cheng Yu

Cold-formed steel framed shear wall sheathed with corrugated steel sheets is a promising shear wall system for low- and mid-rise constructions at high wind and seismic zones due to its advantages of non-combustibility, high shear strength, and high shear stiffness. Monotonic and cyclic tests on full-scale wall assemblies using corrugated steel sheathing was conducted. To investigate the effect of vertical/gravity loading, shear wall specimens were tested under two different loading conditions: lateral loading, and a combined lateral and vertical/gravity loading. The test results are presented and discussed in this paper. Besides, finite element model of the proposed shear wall was created in Abaqus software. The validity of the numerical model was verified based on the test results. A series of parametric analysis were conducted, including the thickness of framing members, the cross section of stud members, yield strength of the frame members, stud spacing, and the influence of gravity loads. The detailed modeling information, relevant parametric analysis and recommendations for practical application of this type of shear resisting system are also presented.


CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 502-522
Author(s):  
Anton Bogdanić ◽  
Daniele Casucci ◽  
Joško Ožbolt

Concrete splitting failure due to tension load can occur when fastening systems are located close to an edge or corner of a concrete member, especially in thin members. This failure mode has not been extensively investigated for anchor channels. Given the current trend in the construction industry towards more slender concrete members, this failure mode will become more and more relevant. In addition, significantly different design rules in the United States and Europe indicate the need for harmonization between codes. Therefore, an extensive numerical parametric study was carried out to evaluate the influence of member thickness, edge distance, and anchor spacing on the capacity of anchor channels in uncracked and unreinforced concrete members. One of the main findings was that the characteristic edge distance depends on the member thickness and can be larger than 3hef (hef = embedment depth) for thin members. Based on the numerical and experimental test results, modifications of the design recommendations for the splitting failure mode are proposed. Overall, the authors recommend performing the splitting verification separately from the concrete breakout to design anchor channels in thin members more accurately.


1984 ◽  
Vol 11 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Robert Loov

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.


2011 ◽  
Vol 201-203 ◽  
pp. 2900-2903 ◽  
Author(s):  
Chui Huon Tina Ting ◽  
Hieng Ho Lau

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.


Author(s):  
Zhanchong Shi ◽  
Qingtian Su ◽  
Xinyi He ◽  
Quanlu Wang ◽  
Kege Zhou ◽  
...  

<p>In order to solve the construction problem of perforating rebars’ precise location and it’s getting through the circular holes for the the conventional perfobond connector, a new type of perfobond connector with boot shaped slots was proposed. This new type perfobond connector has the advantage of convenient construction and pricise location. Three groups of push-out tests with nine specimens were carried out to study the shear capacity of the new type perfobond connector. The effect of the number and the spacing of boot shaped slots on failure modes, shear capacity, peak slip and shear stiffness were mainly studied. The test results show that the new type of perfobond connector with boot shaped slots has a high shear capacity and a good ductility, it could be widely applied on the connection between the steel and the concrete structures.</p>


1998 ◽  
Vol 02 (03) ◽  
pp. 247-255
Author(s):  
Temitope O. Alonge ◽  
Olusola O. A. Oni ◽  
Colin J. Morrison

The compressive and shear stiffness of periarticular osteophytes, hypertrophic femoral intercondylar notch and normal articular cartilage were compared by obtaining force-indentation curves and applying a shear force to the cartilage/bone interface. The primary stiffness (at 0–100N load) was similar for osteophytes (391N/mm), intercondylar notch (400N/mm) and normal articular cartilage (401N/mm). By contrast, the secondary stiffness (at 100–500N load) was much higher for the intercondylar notch (493N/mm) compared to the osteophytes (410N/mm). There were two varieties of osteophytes, "pink" and "white". Compared with "pink" osteophytes, "white" osteophytes exhibited features similar to a progressively hardening material and appear to be a more mechanically suitable material as an osteochondral graft for full thickness articular cartilage defect. The shear characteristics of all the samples were similar.


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.


2019 ◽  
Vol 136 ◽  
pp. 50-63 ◽  
Author(s):  
Nima Talebian ◽  
Benoit P. Gilbert ◽  
Nadia Baldassino ◽  
Hassan Karampour

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