Numerical Analysis of Compressed Cold Formed Steel Members considering Initial Geometric Imperfections

Author(s):  
S.J. de Castro Almeida ◽  
J. Munaiar Neto ◽  
M. Malite
Author(s):  
Mingcai Xu ◽  
C. Guedes Soares

The behavior of long stiffened panels are simulated numerically and compared with test results of axial compression until collapse, to investigate the influence of the stiffener’s geometry. The material and geometric nonlinearities are considered in the simulation. The initial geometric imperfections, which affect the collapse behavior of stiffened panels, are also analyzed. The initial imperfections are assumed to have the shape of the linear buckling mode. Four types of stiffeners are made of mild or high tensile steel for bar stiffeners and mild steel for ‘L’ and ‘U’ stiffeners. To produce adequate boundary conditions at the loaded edges, three bays stiffened panels were used in the tests and in the numerical analysis.


Author(s):  
Gaik A. Manuylov ◽  
Sergey B. Kositsyn ◽  
Irina E. Grudtsyna

The aim of the work is to research the precritical and postcritical equilibrium of the stiffened plates subjected aliquant critical loads. Methods. The finiteelement complex MSC PATRAN - NASTRAN was used in the paper. To simulate the plates, flat four-node elements were used. Calculations taking into account geometric nonlinearity were carried out. The material of the shells was considered absolutely elastic. Results. A technique has been developed to study the stability of reinforced longitudinally compressed plates; the critical forces of the stiffened plates of various thicknesses had been calculated. Graphs of deflections dependences on the value of the compressive load had been constructed. The influence of initial geometric imperfections on the value of the critical loads for stiffened plates has been investigated.


2011 ◽  
Vol 9 (3) ◽  
pp. 367-378
Author(s):  
Miroslav Besevic ◽  
Danijel Kukaras

Analysis of axially compressed steel members made of cold formed profiles presented in this paper was conducted through both experimental and numerical methods. Numerical analysis was conducted by means of "PAK" finite element software designed for nonlinear static and dynamic analysis of structures. Results of numerical analysis included ultimate bearing capacity with corresponding middle section force-deflection graphs and buckling curves. Extensive experimental investigation were also concentrated on determination of bearing capacity and buckling curves. Experiments were conducted on five series with six specimens each for slenderness values of 50, 70, 90, 110 and 120. Compressed simply supported members were analyzed on Amsler Spherical pin support with unique electronical equipment and software. Besides determination of forcedeflection curves, strains were measured in 18 or 12 cross sections along the height of the members. Analysis included comparisons with results obtained by different authors in this field recently published in international journals. Special attention was dedicated to experiments conducted on high strength and stainless steel members.


2019 ◽  
Vol 23 (1) ◽  
pp. 51-64 ◽  
Author(s):  
M Anbarasu

This article mainly investigates the behaviour and strength of built-up battened box column composed of lipped angles under axial compression. Ten specimens were fabricated and tested under pinned with warping-restrained end condition including two different cross-section dimensions of columns with five different geometric lengths. Three material tensile coupon tests were conducted to obtain the material properties of the steel used for fabricating the test specimens. The overall initial geometric imperfections were measured. The plate slenderness, member slenderness, chord slenderness and slenderness of batten plates may affect the compression behaviour of cold-formed steel built-up battened box columns and were accordingly investigated. It was found that the chord slenderness significantly affects the compressive strength of the built-up columns. Test results, including the compression resistances, the load versus displacement responses and the deformed shapes were presented. The test strengths were compared with the design strengths predicted using the North American Specifications (AISI-S100:2016), EuroCode (EN1993-1-3:2006) and design equations proposed by EI Aghoury et al. The design strengths predictions by these two design standards were unconservative, with EI Aghoury et al.’s standard performing better. Finite-element models were developed and verified against the test results.


1986 ◽  
Vol 108 (2) ◽  
pp. 131-137
Author(s):  
D. Moulin

This paper presents a simplified method to analyze the buckling of thin structures like those of Liquid Metal Fast Breeder Reactors (LMFBR). The method is very similar to those used for the buckling of beams and columns with initial geometric imperfections, buckling in the plastic region. Special attention is paid to the strain hardening of material involved and to possible unstable post-buckling behavior. The analytical method uses elastic calculations and diagrams that account for various initial geometric defects. An application of the method is given. A comparison is made with an experimental investigation concerning a representative LMFBR component.


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