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Yong-lin Pi - One of the best experts on this subject based on the ideXlab platform.
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A FURTHER STUDY OF Flexural-Torsional Buckling OF ELASTIC ARCHES
International Journal of Structural Stability and Dynamics, 2020Co-Authors: Yong-lin Pi, Mark A. Bradford, N. S. Trahair, Y. Y. ChenAbstract:This paper uses both a virtual work approach and a static equilibrium approach to study the elastic Flexural-Torsional Buckling of circular arches under uniform bending, or under uniform compression. In most studies of the elastic Flexural-Torsional Buckling of arches under uniform compression produced by uniformly-distributed radial loads, the directions of the radial loads are conventionally assumed not to change but to remain parallel to their initial directions during Buckling. In practice, the uniform compression may be produced by hydrostatic loads or by uniformly-distributed radial loads that are directed to a specific point during Buckling. In addition, there are discrepancies between existing solutions for the elastic Flexural-Torsional Buckling moment and load of arches under uniform bending or under uniform compression which need to be clarified. Closed form solutions for the Buckling moment and load are developed. The discrepancies among the existing solutions for the elastic Flexural-Torsional Buckling moment and load of arches are clarified and the sources for the discrepancies are identified. It is found that the lateral components of hydrostatic loads and of uniformly-distributed radial loads that are always directed toward the center of the arch increase the Flexural-Torsional Buckling resistance of an arch under uniform compression. It is also found that first-order Buckling deformations are sufficient for static equilibrium approaches for the Flexural-Torsional Buckling analysis of arches. The rational static equilibrium approach for the Flexural-Torsional Buckling in the present study is effective.
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Flexural–torsional Buckling of fixed steel arches under uniform bending
Journal of Constructional Steel Research, 2020Co-Authors: M.a. Bradford, Yong-lin PiAbstract:Abstract This paper develops a closed-form solution for the elastic flexural–torsional Buckling of a laterally fixed steel circular arch that is subjected to uniform bending. The formulation makes recourse to an orthogonal rotations matrix in order to derive the finite strains and the energy equation for Buckling. Whilst the flexural–torsional Buckling of pinned arches has received some degree of treatment in the literature, it appears that the flexural–torsional Buckling of fixed arches has not been reported openly. The Buckling solutions are very different from those of pinned arches, and significantly they illustrate that the concept of an ‘effective length’ approach, that is often useful for determining the Buckling response of straight beams or columns, is not applicable for the flexural–torsional Buckling of arches. The ramifications of this observation are that design procedures for the out-of-plane Buckling of pinned arches cannot be used as a basis for design procedures for fixed arches.
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Flexural-Torsional Buckling of Steel Arches under a Localized Uniform Radial-Load Incorporating Shear Deformations
Journal of Structural Engineering-asce, 2019Co-Authors: Hanwen Lu, Yong-lin Pi, Mark A. Bradford, Yonghui Huang, Jiyang FuAbstract:AbstractThis paper concentrates on the laterally Flexural-Torsional Buckling analysis incorporating shear deformations for elastic steel circular arches having boundary rotational restraints under ...
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Flexural-Torsional Buckling Resistance Design of Circular Arches with Elastic End Restraints
Journal of Structural Engineering-asce, 2016Co-Authors: Yong-lin PiAbstract:AbstractThis paper presents the Flexural-Torsional Buckling resistance and design of steel circular arches subjected to uniform compression with elastic end bending restraints by using finite element (FE) numerical analyses. Firstly, effects of geometric and mechanical parameters such as initial imperfections, section types, material properties, slenderness, rise-to-span ratios, and end restraints on Flexural-Torsional Buckling resistances of arches are investigated and are found to be eliminated to a large extent by introducing the normalized slenderness. Then, on the basis of extensive numerical results, a design method is proposed to predict the Flexural-Torsional Buckling resistances of circular arches in uniform compression with elastic end restraints by the column curves according to the normalized slenderness and a specific section type, namely curve ‘a’ for hollow sections, curve ‘b’ for welded box sections, and curve ‘c’ for welded I-sections. Next, the flexural stiffness of an arch is studied, t...
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Flexural-Torsional Buckling and Ultimate Resistance of Parabolic Steel Arches Subjected to Uniformly Distributed Vertical Load
Journal of Structural Engineering-asce, 2014Co-Authors: Yong-lin Pi, Si-yuan ZhaoAbstract:AbstractThis paper focuses on the Flexural-Torsional Buckling and ultimate resistance of parabolic steel arches with box sections subjected to full-span uniformly distributed vertical load by using finite-element numerical analyses. First, analyses on preBuckling internal forces and Flexural-Torsional Buckling loads are performed and compared with the existing theories. They show that parabolic arches under uniformly distributed vertical load are actually subjected to combined axial compressive and in-plane bending actions, rather than pure compression in the classic theory. Because the bending moment is substantial for shallow arches, the classic theory with the assumption of pure compression does not predict exactly the Flexural-Torsional Buckling load. Second, the Flexural-Torsional ultimate resistance of parabolic arches is explored based on extensive finite-element numerical results, resulting in a design method based on a modified slenderness. The rise-to-span ratio is found to have a great effect o...
Mark A. Bradford - One of the best experts on this subject based on the ideXlab platform.
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A FURTHER STUDY OF Flexural-Torsional Buckling OF ELASTIC ARCHES
International Journal of Structural Stability and Dynamics, 2020Co-Authors: Yong-lin Pi, Mark A. Bradford, N. S. Trahair, Y. Y. ChenAbstract:This paper uses both a virtual work approach and a static equilibrium approach to study the elastic Flexural-Torsional Buckling of circular arches under uniform bending, or under uniform compression. In most studies of the elastic Flexural-Torsional Buckling of arches under uniform compression produced by uniformly-distributed radial loads, the directions of the radial loads are conventionally assumed not to change but to remain parallel to their initial directions during Buckling. In practice, the uniform compression may be produced by hydrostatic loads or by uniformly-distributed radial loads that are directed to a specific point during Buckling. In addition, there are discrepancies between existing solutions for the elastic Flexural-Torsional Buckling moment and load of arches under uniform bending or under uniform compression which need to be clarified. Closed form solutions for the Buckling moment and load are developed. The discrepancies among the existing solutions for the elastic Flexural-Torsional Buckling moment and load of arches are clarified and the sources for the discrepancies are identified. It is found that the lateral components of hydrostatic loads and of uniformly-distributed radial loads that are always directed toward the center of the arch increase the Flexural-Torsional Buckling resistance of an arch under uniform compression. It is also found that first-order Buckling deformations are sufficient for static equilibrium approaches for the Flexural-Torsional Buckling analysis of arches. The rational static equilibrium approach for the Flexural-Torsional Buckling in the present study is effective.
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Flexural-Torsional Buckling of Steel Arches under a Localized Uniform Radial-Load Incorporating Shear Deformations
Journal of Structural Engineering-asce, 2019Co-Authors: Hanwen Lu, Yong-lin Pi, Mark A. Bradford, Yonghui Huang, Jiyang FuAbstract:AbstractThis paper concentrates on the laterally Flexural-Torsional Buckling analysis incorporating shear deformations for elastic steel circular arches having boundary rotational restraints under ...
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Flexural-Torsional Buckling of high-strength steel beams
Journal of Constructional Steel Research, 2016Co-Authors: Mark A. BradfordAbstract:Abstract High-strength steel (HSS) is gaining widespread acceptance in contemporary engineering structures, with grades of up to 690 MPa being included in many design standards. However, although strength grades well in excess of 690 MPa are possible with modern metallurgical processes, these are not compliant with most design codes of practice. HSS is advantageous when strength, rather than stiffness, predominates the structural response. When this is the case, HSS is very useful in reducing the self-weight of the structure, as many be needed in structural modification, or in contriving a design that minimises the carbon footprint of the structure. Research on the Flexural-Torsional Buckling of steel structures is extremely abundant in the literature, and guidance in codes is very comprehensive. It is known that the resistance to Flexural-Torsional Buckling depends on the interaction of (i) elastic Buckling; (ii) yielding and post-yielding and (iii) residual stresses. Current design curves are based on the elastic Buckling resistance, which is modified to account for the yield and post-yield response of structural steel and the residual stresses in the cross-section. However, HSS with yield stresses exceeding 690 MPa have somewhat different yield and post-yield characteristics and significantly different patterns of residual stresses when compared with structural steel. This paper uses ABAQUS software to investigate the Flexural-Torsional Buckling strength of HSS I-section beams, by incorporating the stress-strain curves and residual stresses measured experimentally and reported in the literature. With a similar methodology to structural steel members, the interaction of elastic Buckling at the member level with the material characteristics at the cross-sectional level is investigated and a strength design formulation is proposed.
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7.1 – Elastic Flexural-Torsional Buckling of Web-tapered Fabricated Cantilevers
Design Fabrication and Economy of Welded Structures, 2014Co-Authors: Mark A. BradfordAbstract:This paper develops a simple, finite element-based method for predicting the elastic Flexural-Torsional Buckling loads of steel I-section members that contain tapered webs, which are fabricated by welding. The formulation is bifurcative, and is based on a beam or line element with eight assemblable Buckling degrees of freedom. Some previously reported studies have been shown to fail to account for the component of the flange moments during Buckling in the longitudinal direction, which vanishes for a prismatic member, and whose omission leads to erroneous results. The formulation herein accounts for the inclined flange moments. The results of the Buckling analysis are useful, insofar as the Eurocode 3 does not present prescriptive equations for the design of tapered members and directs the user to the results of research studies of the type developed herein. Results are given for tapered cantilever beams.
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Effects of shape functions on flexural–torsional Buckling of fixed circular arches
Engineering Structures, 2014Co-Authors: Yong-lin Pi, Si-yuan Zhao, Mark A. BradfordAbstract:Abstract Because fixed arches have much higher flexural–torsional Buckling resistance than pinended arches, they are used for engineering structures in many cases. However, studies on their flexural–torsional Buckling behaviour have rarely been reported in the open literature hitherto. This paper investigates the elastic flexural–torsional Buckling of fixed circular arches subjected to uniform compression and uniform bending because they play important roles in the design of steel arches against their flexural–torsional failure. One of the major difficulties in solving the flexural–torsional Buckling problem of a fixed arch is to determine its accurate Buckling shapes. The flexural–torsional Buckling shapes are studied using a finite element (FE) method in association with eigenvalue analyses. It is found that the flexural–torsional Buckling shape of a fixed arch becomes more complicated than the case of a straight beam-column or a shallow arch when the rise-to-span ratio increases, and so the theoretical analysis requires more terms of Fourier trigonometric series to describe the Buckling shapes. Based on this, analytical solutions for flexural–torsional Buckling loads of fixed arches are derived both by the Rayleigh–Ritz method and by solving differential equations for Buckling deformations. Comparisons with the FE results show that the analytical solutions by the Rayleigh–Ritz method are reasonably accurate and that the analytical solutions by solving the equations for Buckling deformations are exactly the same as the FE results. Simple approximate formulas for Buckling loads of fixed arches with box-sections are proposed based on the extensive FE results for structural designers to use. The validity of the effective length method for the fixed arches is also discussed. It is found that in the case of circular arches the effective length method should not be used because the rise-to-span ratios and boundary conditions have complicated and significant influence on the Buckling load.
Mahen Mahendran - One of the best experts on this subject based on the ideXlab platform.
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Design of cold-formed steel columns at elevated temperatures subject to Flexural-Torsional Buckling
Science & Engineering Faculty, 2020Co-Authors: Shanmuganathan Gunalan, Deeson Bandula Heva, Mahen MahendranAbstract:Cold-formed steel members are often subject to axial compression loads in a range of applications. These thin-walled members can be subject to various types of Buckling modes, including Flexural-Torsional Buckling. Design standards provide guidelines for columns subject to Flexural-Torsional Buckling modes at ambient temperature. However, there are no specific design guidelines for elevated temperature conditions. Hence extensive research efforts have gone into the many investigations addressing the Flexural-Torsional Buckling behaviour of cold-formed steel columns at elevated temperatures.This research has reviewed the accuracy of the current design rules in AS/NZS 4600 and the North American Specification in determining the member capacities of cold-formed steel columns using the results from detailed finite element analyses and an experimental study of lipped channel columns. It was found that the current ambient temperature Australian and American design rules accurately predicted the member capacities of pin ended lipped channel columns undergoing flexural torsional Buckling at elevated temperatures by simply using the appropriate elevated temperature mechanical properties. However, for fixed ended columns with warping fixity undergoing Flexural-Torsional Buckling, it was found that the current design rules significantly underestimated the column capacities as they disregard the beneficial effect of warping fixity. This research has therefore proposed improved design rules and verified their accuracy using finite element analysis and test results of cold-formed lipped channel columns made of three cross-sections and five different steel grades and thicknesses. This paper presents the details of this research study and the results.
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Flexural–torsional Buckling behaviour and design of cold-formed steel compression members at elevated temperatures
Science & Engineering Faculty, 2020Co-Authors: Shanmuganathan Gunalan, Yasintha Bandula Heva, Mahen MahendranAbstract:Current design rules for the member capacities of cold-formed steel columns are based on the same non-dimensional strength curve for both fixed and pinned-ended columns at ambient temperature. This research has investigated the accuracy of using current ambient temperature design rules in Australia/New Zealand (AS/NZS 4600), American (AISI S100) and European (Eurocode 3 Part 1.3) standards in determining the flexural–torsional Buckling capacities of cold-formed steel columns at uniform elevated temperatures using appropriately reduced mechanical properties. It was found that these design rules accurately predicted the member capacities of pin ended lipped channel columns undergoing flexural torsional Buckling at elevated temperatures. However, for fixed ended columns with warping fixity undergoing flexural–torsional Buckling, the current design rules significantly underestimated the column capacities as they disregard the beneficial effect of warping fixity. This paper has therefore recommended the use of improved design rules developed for ambient temperature conditions to predict the axial compression capacities of fixed ended columns subject to flexural–torsional Buckling at elevated temperatures within AS/NZS 4600 and AISI S100 design provisions. The accuracy of the proposed fire design rules was verified using finite element analysis and test results of cold-formed lipped channel columns at elevated temperatures except for low strength steel columns with intermediate slenderness whose behaviour was influenced by the increased nonlinearity in the stress–strain curves at elevated temperatures. Further research is required to include these effects within AS/NZS 4600 and AISI S100 design rules. However, Eurocode 3 Part 1.3 design rules can be used for this purpose by using suitable Buckling curves as recommended in this paper.
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Improved design rules for fixed ended cold-formed steel columns subject to Flexural-Torsional Buckling
Science & Engineering Faculty, 2020Co-Authors: Shanmuganathan Gunalan, Mahen MahendranAbstract:This paper has presented the details of an investigation into the flexural and flexuraltorsional Buckling behaviour of cold-formed structural steel columns with pinned and fixed ends. Current design rules for the member capacities of cold-formed steel columns are based on the same non-dimensional strength curve for both fixed and pinned-ended columns. This research has reviewed the accuracy of the current design rules in AS/NZS 4600 and the North American Specification in determining the member capacities of cold-formed steel columns using the results from detailed finite element analyses and an experimental study of lipped channel columns. It was found that the current Australian and American design rules accurately predicted the member capacities of pin ended lipped channel columns undergoing flexural and flexural torsional Buckling. However, for fixed ended columns with warping fixity undergoing Flexural-Torsional Buckling, it was found that the current design rules significantly underestimated the column capacities as they disregard the beneficial effect of warping fixity. This paper has therefore proposed improved design rules and verified their accuracy using finite element analysis and test results of cold-formed lipped channel columns made of three cross-sections and five different steel grades and thicknesses.
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Flexural-Torsional Buckling Behaviour and Design of Cold-formed Steel Compression Members at Elevated Temperatures
Engineering Structures, 2014Co-Authors: Shanmuganathan Gunalan, Yasintha Bandula Heva, Mahen MahendranAbstract:Current design rules for the member capacities of cold-formed steel columns are based on the same non-dimensional strength curve for both fixed and pinned-ended columns at ambient temperature. This research has investigated the accuracy of using current ambient temperature design rules in Australia/New Zealand (AS/NZS 4600), American (AISI S100) and European (Eurocode 3 Part 1.3) standards in determining the flexural–torsional Buckling capacities of cold-formed steel columns at uniform elevated temperatures using appropriately reduced mechanical properties. It was found that these design rules accurately predicted the member capacities of pin ended lipped channel columns undergoing flexural torsional Buckling at elevated temperatures. However, for fixed ended columns with warping fixity undergoing flexural–torsional Buckling, the current design rules significantly underestimated the column capacities as they disregard the beneficial effect of warping fixity. This paper has therefore recommended the use of improved design rules developed for ambient temperature conditions to predict the axial compression capacities of fixed ended columns subject to flexural–torsional Buckling at elevated temperatures within AS/NZS 4600 and AISI S100 design provisions. The accuracy of the proposed fire design rules was verified using finite element analysis and test results of cold-formed lipped channel columns at elevated temperatures except for low strength steel columns with intermediate slenderness whose behaviour was influenced by the increased nonlinearity in the stress–strain curves at elevated temperatures. Further research is required to include these effects within AS/NZS 4600 and AISI S100 design rules. However, Eurocode 3 Part 1.3 design rules can be used for this purpose by using suitable Buckling curves as recommended in this paper.
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Flexural-Torsional Buckling tests of cold-formed steel compression members at elevated temperatures
Steel and Composite Structures, 2013Co-Authors: Yasintha Bandula Heva, Mahen MahendranAbstract:Current design standards do not provide adequate guidelines for the fire design of cold-formed steel compression members subject to Flexural-Torsional Buckling. Eurocode 3 Part 1.2 (2005) recommends the same fire design guidelines for both hot-rolled and cold-formed steel compression members subject to Flexural-Torsional Buckling although considerable behavioural differences exist between cold-formed and hot-rolled steel members. Past research has recommended the use of ambient temperature cold-formed steel design rules for the fire design of cold-formed steel compression members provided appropriately reduced mechanical properties are used at elevated temperatures. To assess the accuracy of Flexural-Torsional Buckling design rules in both ambient temperature cold-formed steel design and fire design standards, an experimental study of slender cold-formed steel compression members was undertaken at both ambient and elevated temperatures. This paper presents the details of this experimental study, its results, and their comparison with the predictions from the current design rules. It was found that the current ambient temperature design rules are conservative while the fire design rules are overly conservative. Suitable recommendations have been made in relation to the currently available design rules for Flexural-Torsional Buckling including methods of improvement. Most importantly, this paper has addressed the lack of experimental results for slender cold-formed steel columns at elevated temperatures.
M.a. Bradford - One of the best experts on this subject based on the ideXlab platform.
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Flexural–torsional Buckling of fixed steel arches under uniform bending
Journal of Constructional Steel Research, 2020Co-Authors: M.a. Bradford, Yong-lin PiAbstract:Abstract This paper develops a closed-form solution for the elastic flexural–torsional Buckling of a laterally fixed steel circular arch that is subjected to uniform bending. The formulation makes recourse to an orthogonal rotations matrix in order to derive the finite strains and the energy equation for Buckling. Whilst the flexural–torsional Buckling of pinned arches has received some degree of treatment in the literature, it appears that the flexural–torsional Buckling of fixed arches has not been reported openly. The Buckling solutions are very different from those of pinned arches, and significantly they illustrate that the concept of an ‘effective length’ approach, that is often useful for determining the Buckling response of straight beams or columns, is not applicable for the flexural–torsional Buckling of arches. The ramifications of this observation are that design procedures for the out-of-plane Buckling of pinned arches cannot be used as a basis for design procedures for fixed arches.
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Flexural-Torsional Buckling of arches under directed or hydrostatic loads
Fourth International Conference on Advances in Steel Structures, 2007Co-Authors: M.a. Bradford, Yong-lin PiAbstract:Publisher Summary The chapter describes the use an energy approach to study the elastic Flexural-Torsional Buckling of circular arches of doubly symmetric cross-section under uniform compression produced by hydrostatic or uniformly distributed directed radial loads. Closed form solutions for the Buckling loads under these loading conditions are obtained in the chapter. It is found that the Buckling load under hydrostatic uniform radial loads is highest while the Buckling load under conservative uniform radial loads is the lowest. The lateral components of uniformly distributed radial loads that are always directed to the centre of the initial curvature of an arch and of hydrostatic loads increase the Flexural-Torsional Buckling resistance of the arch under uniform compression.
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Flexural-Torsional Buckling of shallow arches with open thin-walled section under uniform radial loads
Thin-walled Structures, 2007Co-Authors: Yong-lin Pi, M.a. BradfordAbstract:An arch with an open thin-walled section that is subjected to a radial load uniformly distributed around the arch axis may suddenly buckle out of its plane of loading and fail in a Flexural-Torsional Buckling mode. The classical Flexural-Torsional Buckling load for an arch with an open thin-walled section under a uniform radial load has been obtained by a number of researchers, based on the consideration that the uniform radial load produces a uniform axial compressive force without in-plane bending prior to the occurrence of Flexural-Torsional Buckling. This assumption is correct for deep arches. However, the uniform radial load may produce substantial bending actions in shallow arches prior to Flexural-Torsional Buckling, and so the classical Buckling analysis based on the assumption of uniform axial compression may produce incorrect Flexural-Torsional Buckling loads for shallow arches. This paper investigates the Flexural-Torsional Buckling of shallow arches with an open thin-walled section that are subjected to a radial load uniformly distributed around the arch axis. It is found that shallow arches under a uniform radial load are subjected to combined in-plane compressive and bending actions prior to Flexural-Torsional Buckling, and that using the classical Buckling solution for circular arches under uniform compression produces incorrect Buckling loads for shallow arches. A rational finite element model is developed for the Flexural-Torsional Buckling and postBuckling analysis of shallow arches with an open thin-walled section, which allows the Buckling loads to be obtained correctly.
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Elastic Flexural-Torsional Buckling and postBuckling of arches subjected to a central concentrated load
2001Co-Authors: Yong-lin Pi, M.a. BradfordAbstract:This paper investigates the elastic Buckling and postBuckling behaviour of arches that are subjected to a central concentrated load, using a finite element model developed by authors. Comparisons with existing experimental and analytical results demonstrate that the model is effective and efficient in terms of accuracy, the number of elements needed for convergence, and the ability to perform a postBuckling analysis. It is found that under a central concentrated load, the elastic Buckling and postBuckling behaviour of a simply supported arch is similar to that of an arch in unform bending or in uniform axial compression. The slenderness of a simply supported arch has almost no effect on its Buckling behaviour. However, the slenderness of all but very stocky pin-ended arches has significant effects on their Buckling behaviour. For shallow pinended arches, the elastic Flexural-Torsional Buckling load is reduced significantly by the large axial compression developed in the arch prior to Buckling. As the included angle increases, the Buckling load of the pin-ended arch decreases significantly until a minimum value of the Buckling load is reached, and then increases. The increase of the Buckling load stops at a certain value of the included angle, and thereafter the Buckling load steadily decreases with the increase of the included angle. For stocky pin-ended arches, the Buckling load decreases steadily with the increase of the included angle. The slenderness of deep pin-ended arches has a very small effect on their Buckling behaviour. There is a substantial postBuckling response for shallow pin-ended arches, due to relaxation of the axial compression after Buckling. The slenderness of fixed arches has a significant effect on their Buckling behaviour. The large axial compression developed in shallow fixed arches reduces the elastic Flexural-Torsional Buckling loads significantly. Shallow fixed arches also have a substantial postBuckling response due to the relaxation of the axial compression and the moment redistribution in the postBuckling range. For slender fixed arches with moderate or large included angles, four inflexion points can be developed in their deformed profile, which reduces their effective length and leads to a significant increase of their Flexural-Torsional Buckling load. After Buckling, a redistribution of bending moment takes place which increases the moments at the supports and decreases the moment at mid-span, thereby increasing the postBuckling strengths. For stocky fixed arches, however, only two inflexion points can be developed in their deformed profile prior to Buckling and the Buckling load decreases slightly as the included angle increases.
Kim J.r. Rasmussen - One of the best experts on this subject based on the ideXlab platform.
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Flexural–torsional Buckling of ultra light-gauge steel storage rack uprights
Thin-walled Structures, 2014Co-Authors: A.n. Trouncer, Kim J.r. RasmussenAbstract:Abstract This paper presents an experimental investigation into the behaviour of ultra light-gauge steel storage rack uprights subjected to compression. Two different types of members with varying lengths are tested and while the combined effects of local and distortional Buckling are investigated, special attention is given to longer specimens that fail by flexural–torsional Buckling in combination with local and distortional Buckling. Deformations experienced during testing by all of the specimens were measured and observations regarding failure modes have been documented. In addition, the geometric imperfections of each member were measured before testing, as were the material properties of the cold-rolled sections and the virgin steel from which the sections were formed. This paper details the observed failure modes, the recorded ultimate strengths and the load-deflection responses. Design capacities calculated from AS/NZS 4084 (2012) [1] , RMI (2012) [2] and EN 15512 (2009) [3] specifications are then evaluated and compared to the experimental results obtained.The evaluation of international specificationsdetermined that EN 15512 (2009) [3] is more accurate in predicting ultimate loads of sections undergoing interactive Buckling than both AS/NZS 4804 (2012) [1] and RMI (2012) [2] .
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Combined Distortional and Overall Flexural-Torsional Buckling of Cold-Formed Stainless Steel Sections: Experimental Investigations
Journal of Structural Engineering-asce, 2010Co-Authors: Barbara Rossi, Jean-pierre Jaspart, Kim J.r. RasmussenAbstract:This paper presents a series of 48 full-scale tests on press-braked stainless steel lipped channel section columns subjected to concentric compression. The tests were carried out between fixed ends in the Structures Laboratory of the University of Liege and the test specimens were designed such that distortional Buckling developed in the section prior to overall Flexural-Torsional Buckling. The stainless steel alloy was 1.4003 chromium weldable steel, popularly known as 3Cr12. Three different geometries were tested using the same experimental setup. A critical summary of the standards and methods for calculating the carrying capacity of cold-formed stainless steel compression members is presented in a companion paper by the same writers.
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Combined Distortional and Overall Flexural-Torsional Buckling of Cold-Formed Stainless Steel Sections: Design
Journal of Structural Engineering-asce, 2010Co-Authors: Barbara Rossi, Jean-pierre Jaspart, Kim J.r. RasmussenAbstract:This paper provides a critical summary of the European standards and design methods available for calculating the strength of cold-formed stainless steel compression members. The standards considered (so far mainly applied to columns failing by flexural Buckling) are applied to the case of lipped channel section columns failing by combined distortional and overall Flexural-Torsional Buckling. As observed during the tests presented in a companion paper, distortional Buckling is found to have a considerable effect on the cross section resistance and is prone to interact with the global Flexural-Torsional mode. It is investigated how the different formulations account for the two Buckling modes and their interaction and how accurate strength predictions they provide. A new direct strength method taking into account these failure modes is then presented and compared to the test results.