Experimental Investigation of the Deformation of Built-up Members of Cold-Formed Steel Profiles

2011 ◽  
Vol 70 ◽  
pp. 416-421 ◽  
Author(s):  
Iveta Georgieva ◽  
Luc Schueremans ◽  
Guido De Roeck ◽  
Lincy Pyl
Keyword(s):  
Cross Section ◽  
Local Buckling ◽  
Element Model ◽  
Mode Shapes ◽  
European Standard ◽  
Distortional Buckling ◽  
Buckling Mode ◽  
Measuring Device ◽  
Measuring Techniques ◽  
Cold Formed Steel

Built-up members of cold-formed steel (CFS) profiles were tested in 4-point bending. CFS profiles (generally thin-walled) deform considerably under load, and the deformed configuration is a result of the superposition of different buckling mode shapes. Local buckling propagates through the profile walls; during distortional buckling parts of the cross-section rotate around a web-flange juncture. Alongside the buckling effects, the overall deformation of the member is considerable. To study these slender and relatively long members, a sufficient number of measuring positions on the specimens is needed. Often, this is not feasible with the conventional measuring techniques. An optical measuring device was used to record the movement of a large number of points per specimen. The obtained results are placed in a 3D coordinate system and can be exported for further data processing. The goal of the measurement campaign was to calibrate a Finite Element model that will simulate the tests. The model will be used for the analysis of composed frame members of CFS profiles, whose design is not entirely covered by the European Standard [1]. After calibration, the FEA predicts the performance of these built-up members well.

Experiments on Cold-Formed Steel Lipped Channel Beams with Complex Edge Stiffeners and Web Holes

2013 ◽  
Vol 671-674 ◽  
pp. 461-464
Author(s):  
Chun Gang Wang ◽  
Run Jia Liang ◽  
Lian Guang Jia ◽  
Hong Liu
Keyword(s):  
Bending Strength ◽  
Great Influence ◽  
Local Buckling ◽  
Experimental Results ◽  
Distortional Buckling ◽  
Buckling Mode ◽  
Element Analysis ◽  
Web Stiffeners ◽  
Cold Formed Steel ◽  
And Behavior

This paper presents an experimental investigation and a numerical analysis on the bending strength and behavior of cold-formed steel C-section and ∑-section beams with complex edge stiffeners and web holes. Local buckling, distortional buckling and interaction between local and distortional buckling were observed in the tests. The experimental results show that the stiffened web has great influence on member's bending strength. Compared with C-section specimens, the stiffness of the web stiffeners of ∑-section specimens reduced the influence of the holes. The finite element analysis results show good agreement with the experimental results in terms of bending strength and buckling mode.

Distortional buckling of compressed cold‐formed lipped C channels via buckling mode shapes

ce/papers ◽  
2021 ◽  
Vol 4 (2-4) ◽  
pp. 2535-2541
Author(s):  
Bálint Vaszilievits‐Sömjén
Keyword(s):  
Mode Shapes ◽  
Distortional Buckling ◽  
Buckling Mode

Experimental Study on Mechanical Behavior of Cold-Formed Steel Three Limbs Built-up Section Members

2010 ◽  
Vol 163-167 ◽  
pp. 651-654
Author(s):  
Tian Hua Zhou ◽  
Shao Feng Nie ◽  
Xiang Bin Liu ◽  
Guang Yi Li
Keyword(s):  
Experimental Study ◽  
Mechanical Behavior ◽  
Axial Compression ◽  
Local Buckling ◽  
Distortional Buckling ◽  
Torsional Buckling ◽  
Failure Characteristics ◽  
Compression Load ◽  
Cold Formed Steel ◽  
Flexural Torsional Buckling

18 specimens of cold-formed steel three limbs built-up section members are tested under axial compression load in this paper. The section forms are divided into two categories: A and B. Load-displacement (P-Δ) curves and failure characteristics of specimens are obtained. The results show that: As to section A members, the failure characteristics of LC, MC and SC series of specimens are flexural-torsional buckling, torsional buckling and distortional buckling, local buckling and distortional buckling. As to section B members, the failure characteristics of LC, MC series of specimens are flexural buckling, while local buckling and distortional buckling for members of SC series.

Lipped channel cold-formed steel columns under local-distortional buckling mode interaction

2019 ◽  
Vol 137 ◽  
pp. 251-270 ◽  
Author(s):  
Gustavo Y. Matsubara ◽  
Eduardo de M. Batista ◽  
Guilherme C. Salles
Keyword(s):  
Mode Interaction ◽  
Distortional Buckling ◽  
Buckling Mode ◽  
Steel Columns ◽  
Cold Formed Steel

Support-Condition Analyses of Rotating Beams Under Distributed Imbalance Loading

2011 ◽  
Author(s):  
Kai Jokinen ◽  
Erno Keskinen ◽  
Marko Jorkama ◽  
Wolfgang Seemann
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cross Section ◽  
Cross Sections ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Constant Cross Section ◽  
Support Condition ◽  
Beam Elements

In roll balancing the behaviour of the roll can be studied either experimentally with trial weights or, if the roll dimensions are known, analytically by forming a model of the roll to solve response to imbalance. Essential focus in roll balancing is to find the correct amount and placing for the balancing mass or masses. If this selection is done analytically the roll model used in calculations has significant effect to the balancing result. In this paper three different analytic methods are compared. In first method the mode shapes of the roll are defined piece wisely. The roll is divided in to five parts having different cross sections, two shafts, two roll ends and a shell tube of the roll. Two boundary conditions are found for both supports of the roll and four combining equations are written to the interfaces of different roll parts. Totally 20 equations are established to solve the natural frequencies and to form the mode shapes of the non-uniform roll. In second model the flexibility of shafts and the stiffness of the roll ends are added to the support stiffness as serial springs and the roll is modelled as a one flexibly supported beam having constant cross section. Finally the responses to imbalance of previous models are compared to finite element model using beam elements. Benefits and limitations of each three model are then discussed.

Optical Measuring Technique for the Investigation of Built-Up Cold-Formed Steel Structural Members

2011 ◽  
Vol 473 ◽  
pp. 343-351 ◽  
Author(s):  
Iveta Georgieva ◽  
Luc Schueremans ◽  
Guido De Roeck ◽  
Lincy Pyl
Keyword(s):  
Local Buckling ◽  
Structural Members ◽  
Distortional Buckling ◽  
Residential Housing ◽  
3D Motion Analysis ◽  
Vertical Displacements ◽  
Global Buckling ◽  
Cold Formed Steel ◽  
Thin Walled ◽  
Displacement Transducers

The construction industry uses cold-formed steel (CFS) sheets in the form of galvanised thin-walled profiles and corrugated sheets. In the past decade, CFS profiles have been competing with their hot-rolled counterparts as primary structural members of industrial halls, office buildings and residential housing of up to 3-4 storeys. The spans and column heights achieved with CFS profiles are ever larger. Due to the large slenderness of these members, adequate strength and stability are necessary, as well as reliability in design. Thin-walled members go through buckling during all stages of their working life. Local buckling appears at loads sometimes much lower than the design load. Distortional buckling seriously reduces the member resistance. It interacts with warping and lateral-torsional buckling, being significant for these asymmetric open sections. To restrict these effects, builders employ double sections - usually two standard cold-formed shapes bolted together to form a built-up section. These sections have the advantages of symmetry, higher stability and strength. The design of built-up members involves many uncertainties - although the European standard includes guidelines on the prediction of local, distortional and global buckling, the partial integrity and interaction between the parts of the composed members is still not studied. To study the actual behaviour, built-up members are tested in bending. An optical device for 3D motion analysis measures the displacement of points of interest on the specimen. Two interacting cameras use parallax to obtain the position of an arbitrary number of reflective markers glued to the specimen. The device tracks the movement of the markers in a 3D coordinate system without any contact with the specimen. Standard displacement transducers measure vertical displacements to validate the results. The paper gives an appraisal of the applicability of the method, a summary of the difficulties faced and the outcome of the test campaign.

scholarly journals An Optimization Procedure for Overhead Gantry Crane Exposed to Buckling and Yield Criteria

2017 ◽  
Vol 8 (2) ◽  
pp. 28
Author(s):  
Ali Ahmid ◽  
Van N. Le ◽  
Thien M. Dao
Keyword(s):  
Cross Section ◽  
Real Life ◽  
Local Buckling ◽  
Beam Theory ◽  
Optimization Procedure ◽  
Element Model ◽  
Gantry Crane ◽  
Rectangular Plates ◽  
Cross Section Area ◽  
Structural Applications

<p>The current study presents a general optimization procedure that could be used in designing of various structural applications. To validate the performance of the proposed procedure, a real life application of a custom welded I-Beam gantry crane is selected. The crane is composed of three rectangular plates with the same length and different thicknesses and widths welded together by full penetration welds over the span length to form an I-Beam profile. The thicknesses and widths of plates are to be optimized to have the minimum cross section area while respecting yield, buckling, deflection and fatigue criteria. A mathematical procedure based on Timoshenko beam theory and Crane Manufacturers Association of America (CMAA) in combination with the Genetic Algorithm (GA) is presented, and a Mathcad code is implemented to find the optimal I-Beam cross section dimensions. Nine examples are introduced for 8, 12 and 20 m crane span subjected to 10, 20 and 40-toncapacities. It is noticed that the optimized I-section configurations always show narrow and thick lower flange, wider and thinner upper flange and tall and very thin web. Theupper flange local buckling and the lateral buckling limits are achieved for all nine cases, 75% of cases for the web buckling limit, about 33% of cases for the fatigue and yield limits whereas the maximum deflection constraint is never critical. The obtained results were verified using ANSYS Workbench software with a 3D Solid Finite Element model and shown good agreement, which confirms that the proposed procedure is efficient.</p>

Comparison on Section Properties and Flexural Behaviour for Cold-Formed Steel Built-Up Section

2015 ◽  
Vol 735 ◽  
pp. 80-84 ◽  
Author(s):  
Yeong Huei Lee ◽  
Shahrin Mohammad ◽  
Yee Ling Lee
Keyword(s):  
Experimental Study ◽  
Local Buckling ◽  
Effective Width ◽  
Sectional Area ◽  
Flexural Behaviour ◽  
Distortional Buckling ◽  
Steel Sections ◽  
Cold Formed Steel ◽  
Flexural Resistance ◽  
Good Agreement

This paper performs analytical and experimental investigation on the section properties of locally produced cold-formed steel sections. Effective width method given by BS EN1993-1-3 is used to calculate the section properties for two slender cold-formed steel channel sections, namely KS200C20 and KS250C20. Local buckling and distortional buckling are taken into account in the calculation. Effective width method has significantly reduced the full sectional area and thus gives a relative lower value for the sectional resistance of cold-formed steel channel sections. The analytical results is compared to manufacturer’s data and differences of not more than 3.37% is recorded. Experimental study on the flexural behaviour on the two types of cold-formed steel channel sections is carried out. The results show that BS EN1993-1-3 has good agreement with experimental results for flexural resistance that included local and distortional buckling consideration. It is concluded that effective width method by BS EN1993-1-3 is suitable to calculate the section properties of of locally produced cold-formed steel channel sections.

Local Buckling of Cold-Formed Steel Members with Edge Stiffened Holes

2015 ◽  
Vol 725-726 ◽  
pp. 697-702 ◽  
Author(s):  
Marsel Garifullin ◽  
Darya Trubina ◽  
Nikolai Vatin
Keyword(s):  
Local Buckling ◽  
Buckling Analysis ◽  
Numerical Results ◽  
Building Industry ◽  
Elastic Buckling ◽  
Distortional Buckling ◽  
Steel Members ◽  
Cold Formed Steel ◽  
New Generation

Cold formed steel members with edge stiffened holes are a new generation of cold formed members recently developed by the building industry. Very little research has been performed on such sections to determine their local and distortional buckling capacity. This article provides the numerical results of elastic local buckling analysis of cold-formed lipped channels with edge stiffened holes. For flexural elements values of critical buckling moments are calculated and the influence of hole spacing and diameter on elastic buckling capacity is determined.

scholarly journals Experimental Study and Proposal to Improve the EWM Design of Cold-Formed Steel Lipped Channel Columns with Circular Holes under Axial Compression

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Xingyou Yao
Keyword(s):  
Circular Hole ◽  
Axial Compression ◽  
Design Method ◽  
Local Buckling ◽  
Effective Width ◽  
Distortional Buckling ◽  
Channel Section ◽  
Circular Holes ◽  
Failure Loads ◽  
Cold Formed Steel

The cold-formed steel (CFS) lipped channel section with circular holes has been widely used in low-rise and multistory building structures as the column. However, the circular hole in the web makes the lipped channel column become susceptible to buckle. A total of 54 CFS lipped channel axial compression columns with and without circular holes were used to study the buckling behavior and the effective width design method. The interaction of the local buckling and the distortional buckling were observed for the short and intermediate columns, while the slender columns were controlled by the interaction of the local buckling, distortional buckling, and flexural buckling or flexural-torsional buckling. The experimental failure loads were gradually decreased with the increase in the diameter of the circular hole for the specimens with the same section. The failure loads of the specimens with two holes were lower than those of the specimens with one hole with same section and same diameter of holes. Then, the experimental results were used to validate a nonlinear finite element model (FEM) previously developed by the authors. The validated FEM was subsequently used to obtain additional 36 numerical failure results concerning the effects of the length, the section, and the diameter and the number of the circular holes. Furthermore, the proposal to calculate the distortional buckling coefficient of the CFS lipped channel section with circular holes were put forward based on numerical analysis considering the reduction of effect of holes. Finally, a proposal to improve the effective width method (EWM) design approach for CFS lipped channel sections with circular holes under axial compression was presented. The comparisons between experimental and numerical capacities and their calculations provided by the proposed EWM design method illustrate a great application of the proposed approach.

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