Behaviour of cold-formed stainless steel stub columns under bending and axial loading

This paper is concerned with the ultimate load capacity of non-perforated and perforated equal-angle cold-formed steel stub columns. An experimental study has been undertaken to investigate the behavior of such members and several column specimens were tested to failure under axial or eccentric loading. The experimental results were used to establish the accuracy of a finite element model proposed in this study and the modeling was used to carry out a parametric study

Post-elastic Capacity of Thin-walled Cold-formed Steel Members

The paper presents the possibility to apply the local plastic mechanisms to characterize the ultimate strength of thin-walled cold-formed steel members subjected to eccentric compression. In previous papers [13], [14], [18], the authors have shown that, for compression or bending, the failure of such sections modelled by localized plastic mechanisms characterize better the behaviour of thin-walled cold-formed short members in Ultimate Limit State. These models are consistent with the real failure mechanism of short members and were confirmed both by experimental tests and advanced elastic-plastic FEM analyses. Selected results from these studies are summarized in Chapter 2 of the paper. The main aim of the actual paper concerns the more complex problem of members subjected to combined loadings i.e. compression and bending or eccentric compression. The failure model of slender members in eccentric compression is still an open question. In an attempt to solve this problem, the authors propose a consistent methodology which applies the General Method of EN1993 Part 1-1, in which the section resistance, prone to bending and compression, is characterized through plastic mechanism failure models.This work was supported by The Polish - Romanian Joint Research Project: Yield line theory for load-capacity estimation of thin-walled cold-formed steel members under combined loading, 2019-2021, under the agreement on scientific cooperation between the Polish Academy of Sciences and the Romanian Academy, project PN-III-CEI- EUREKA-2019/E113493 - CFSExpert - Structural design tool for cold-formed steel structures, CCCDI - UEFISCDI, Romanian Ministry of Research and Innovation and project 10PFE/2018, PERFORM-TECH-UPT - The increasing of the institutional performance of the Polytechnic University of Timișoara by strengthening the research, development and technological transfer capacity in the field of "Energy, Environment and Climate Change", PNCDI III, Romanian Ministry of Research and Innovation

Stainless steel stub columns subject to combined bending and axial loading

This paper examines the behaviour of cold-formed stainless steel stub columns where the material follows a Ramberg-Osgood stress-strain law. The stub column length is varied to examine the effects on the failure capacity when the stub columns are subjected to varying magnitudes of combined bending and axial compression loading. The paper follows the work reported by the same authors in 2003 [Macdonald, M, Rhodes J. and Kotelko M. Behaviour of stainless steel columns under combined bending and axial compression loading. Proceedings of the 10th Symposium on Stability of Structures, Zakopane, Poland. 2003], but here, three different methods of analysis are employed: (i) the Eurocode 3, Part 1.4 design code using an enhanced 0.2% proof stress combined with a full section moment capacity within the interaction formula with nominal levels of loading eccentricity, (ii) the same approach using the Polish cold formed carbon steel code PN-90/B-03200 to ascertain its applicability and (iii), the same approaches but using the true eccentricity with reference to the unsupported length of the columns. The results are compared with those obtained from a series of compression tests performed on cold-formed stainless steel Type 304 stub columns of lipped channel cross-section for the same conditions

Post-elastic Capacity of Thin-walled Cold-formed Steel Members

The paper presents the possibility to apply the local plastic mechanisms to characterize the ultimate strength of thin-walled cold-formed steel members subjected to eccentric compression. In previous papers [13], [14], [18], the authors have shown that, for compression or bending, the failure of such sections modelled by localized plastic mechanisms characterize better the behaviour of thin-walled cold-formed short members in Ultimate Limit State. These models are consistent with the real failure mechanism of short members and were confirmed both by experimental tests and advanced elastic-plastic FEM analyses. Selected results from these studies are summarized in Chapter 2 of the paper. The main aim of the actual paper concerns the more complex problem of members subjected to combined loadings i.e. compression and bending or eccentric compression. The failure model of slender members in eccentric compression is still an open question. In an attempt to solve this problem, the authors propose a consistent methodology which applies the General Method of EN1993 Part 1-1, in which the section resistance, prone to bending and compression, is characterized through plastic mechanism failure models.This work was supported by The Polish - Romanian Joint Research Project: Yield line theory for load-capacity estimation of thin-walled cold-formed steel members under combined loading, 2019-2021, under the agreement on scientific cooperation between the Polish Academy of Sciences and the Romanian Academy, project PN-III-CEI- EUREKA-2019/E113493 - CFSExpert - Structural design tool for cold-formed steel structures, CCCDI - UEFISCDI, Romanian Ministry of Research and Innovation and project 10PFE/2018, PERFORM-TECH-UPT - The increasing of the institutional performance of the Polytechnic University of Timișoara by strengthening the research, development and technological transfer capacity in the field of "Energy, Environment and Climate Change", PNCDI III, Romanian Ministry of Research and Innovation

Load capacity of combined steel/aluminium members under bending action - experimental study

A study of the bending action and load capacity of combined steel/aluminium members

Stability of structures

This special issue contains almost all of the papers presented during the XIth Symposium on Stability of Structures held in Zakopane (Poland) on 11–15 September 2006, organized by the Department of Strength of Materials and Structures, Technical University of Lodz and the Lodz branch of the Polish Society of Theoretical and Applied Mechanics. The 29 papers consisted of four keynote lectures together with 25 papers presented during the Symposium. The Stability of Structures Symposium has been organized for 44 years. The first of these took place in Lodz (Poland) in May 1963 due to the initiative of the late Professor Jerzy Leyko, the father of the “Stability of Structures School of Lodz” well recognized in Poland. He was the chairman of several of the Symposia and invited foreign guest researchers working in the domain of stability of structures to participate. The Symposium became a permanent event in the calendar of Polish scientific conferences. For many years, the participation of foreign guests from the Czech Republic, Great Britain, Japan, Russia, Slovakia and Ukraine has raised the rank of this monothematic conference. For the past 10 years, the Symposia have been held in Zakopane, the capital of the Polish Tatra Mountains

Web crippling behaviour of thin-walled lipped channel beams

This paper presents the results of an investigation into web crippling behaviour—conducted on cold-formed thin-walled steel lipped channel beams subjected to Interior-One-Flange (IOF), Interior-Two-Flange (ITF), End-One-Flange (EOF) and End-Two-Flange (ETF) loading conditions as defined by the American Iron and Steel Institute (AISI). An experimental program was designed to obtain the load-deformation characteristics of beam members with varying cross-sectional and loading parameters under the three web crippling loading conditions. The results obtained from the experiments comprised of the ultimate web crippling strength values and displacements of the thirty-six beam specimens tested. Nonlinear finite element models were developed to simulate web crippling failure of the two loading conditions considered in the experimental program. Also, a combination of elastic analysis with a plastic mechanism approach was employed to investigate the load-deformation characteristics of lipped channel members subjected to the IOF loading condition. The comparison of experimental, finite element and plastic mechanism approach results revealed that the nonlinear finite element models were best capable of closely simulating the web crippling failure behaviour observed in the experiments for all ranges of displacement. Web crippling strength predicted from the Eurocode 3, Part 1.3 [1], and the Polish PN-B-0327 [2] design specifications were also compared with the experimental results and the comparisons indicated considerable underestimations for the range of specimens under EOF and ETF loading conditions