scholarly journals Plastic Mechanisms for Thin-Walled Cold-Formed Steel Members in Eccentric Compression

2016 ◽  
Vol 10 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Viorel Ungureanu ◽  
Maria Kotełko ◽  
Jan Grudziecki
Keyword(s):  
Load Capacity ◽  
Local Buckling ◽  
Minor Axis ◽  
Local Plastic ◽  
Eccentric Compression ◽  
Steel Members ◽  
Plastic Mechanism ◽  
Eurocode 3 ◽  
Cold Formed Steel ◽  
Thin Walled

Abstract The Eurocode 3 concerning thin-walled steel members divides members subjected to compression into four classes, considering their ductility. The representatives of the class C4 are short bars, for which the load-capacity corresponds to the maximum compression stresses less than the yield stress. There are bars prone to local buckling in the elastic range and they do not have a real post-elastic capacity. The failure at ultimate stage of such members, either in compression or bending, always occurs by forming a local plastic mechanism. This fact suggests the possibility to use the local plastic mechanism to characterise the ultimate strength of such members. The present paper is based on previous studies and some latest investigations of the authors, as well as the literature collected data. It represents an attempt to study the plastic mechanisms for members in eccentric compression about minor axis and the evolution of plastic mechanisms, considering several types of lipped channel sections.

scholarly journals Behaviour of thin-walled cold-formed steel members in eccentric compression

2018 ◽  
Author(s):  
Viorel Ungureanu ◽  
Maria Kotełko ◽  
Łukasz Borkowski ◽  
Jan Grudziecki
Keyword(s):  
Eccentric Compression ◽  
Steel Members ◽  
Cold Formed Steel ◽  
Thin Walled

scholarly journals Plastic mechanisms of thin-walled cold-formed steel members in eccentric compression

2018 ◽  
Vol 128 ◽  
pp. 184-192 ◽  
Author(s):  
Viorel Ungureanu ◽  
Maria Kotełko ◽  
Anna Karmazyn ◽  
Dan Dubina
Keyword(s):  
Eccentric Compression ◽  
Steel Members ◽  
Cold Formed Steel ◽  
Thin Walled

scholarly journals Experimental Study on the Effect of Heel Plate Length on the Structural Integrity of Cold-formed Steel Roof Trusses

2018 ◽  
Vol 65 ◽  
pp. 08010
Author(s):  
Je Chenn Gan ◽  
Jee Hock Lim ◽  
Siong Kang Lim ◽  
Horng Sheng Lin
Keyword(s):  
Ultimate Load ◽  
Structural Integrity ◽  
Load Capacity ◽  
Local Buckling ◽  
Ultimate Capacity ◽  
Ultimate Load Capacity ◽  
Plate Length ◽  
Roof Truss ◽  
Cold Formed Steel ◽  
Structural Failures

Applications of Cold-Formed Steel (CFS) are widely used in buildings, machinery and etc. Many researchers began the research of CFS as a roof truss system. It is required to increase the knowledge of the configurations of CFS roof trusses due to the uncertainty of the structural failures regarding the materials and rigidity of joints. The objective of this research is to investigate the effect of heel plate length to the ultimate load capacity of CFS roof truss system. Three different lengths of heel plate specimens were fabricated and subjected to concentrated loads until failure. The highest ultimate capacity for the experiment was 30 kN. The results showed that the increment of the length of the heel plate had slightly increased the ultimate capacity and strain. The increment of the length of the heel plate had increased the deflection of the bottom chords but decreased the deflection of the top chords. Local buckling of top chords adjacent to the heel plate was the primary failure mode for all the heel plate specimens.

scholarly journals Koiter Asymptotic Analysis Of Thin-Walled Cold-Formed Steel Members

2015 ◽  
Vol 9 (4) ◽  
pp. 245-251 ◽  
Author(s):  
Viorel Ungureanu ◽  
Dan Dubina ◽  
Andrei Crisan ◽  
Antonio Madeo ◽  
Giuseppe Zagari ◽  
...  
Keyword(s):  
Experimental Study ◽  
Statistical Evaluation ◽  
Computational Cost ◽  
Limit Load ◽  
Imperfection Sensitivity ◽  
Critical Buckling Load ◽  
Steel Members ◽  
Cold Formed Steel ◽  
Thin Walled ◽  
Low Computational Cost

Abstract An imperfection sensitivity analysis of cold-formed steel members in compression is presented. The analysis is based on Koiter’s approach and Monte Carlo simulation. If the modes interaction is correctly accounted, than the limit load and the erosion of critical buckling load can be easily evaluated. Thousands of imperfection can be analysed with very low computational cost and an effective statistical evaluation of limit performance can be carried out. The analysis is done on pallet rack uprights in compression, based on an intensive experimental study carried out at the Politehnica University of Timisoara.

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.

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