Techno Press
Tp_Editing System.E (TES.E)
Login Search


scs
 
CONTENTS
Volume 6, Number 4, August 2006
 

Abstract
This paper describes the design and behaviour of cold-formed stainless steel slender circular hollow section columns. The columns were compressed between fixed ends at different column lengths. The investigation focused on large diameter-to-plate thickness (D/t) ratio ranged from 100 to 200. An accurate finite element model has been developed. The initial local and overall geometric imperfections have been included in the finite element model. The material nonlinearity of the cold-formed stainless steel sections was incorporated in the model. The column strengths, load-shortening curves as well as failure modes were predicted using the finite element model. The nonlinear finite element model was verified against test results. An extensive parametric study was carried out to study the effects of cross-section geometries on the strength and behaviour of stainless steel slender circular hollow section columns with large D/t ratio. The column strengths predicted from the parametric study were compared with the design strengths calculated using the American Specification, Australian/New Zealand Standard and European Code for cold-formed stainless steel structures. It is shown that the design strengths obtained using the Australian/New Zealand and European specifications are generally unconservative for the cold-formed stainless steel slender circular hollow section columns, while the American Specification is generally quite conservative. Therefore, design equation was proposed in this study.

Key Words
cold-formed; columns; circular hollow sections; finite element; modeling; slender sections; stainless steel; structural design.

Address
Ben Young; Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong KongrnEhab Ellobody; Department of Structural Engineering, Faculty of Engineering, Tanta University, Tanta, Egypt

Abstract
The connection with combined cross diaphragm is developed for the connection of square CFT column and steel beam and proposed to be used for the frame with asymmetric span length. The structural characteristics of this connection lie in the penetration of the beam flange in the direction of major axis through the column for the smooth flow of stress. The purpose of this study is to analyze the dynamic behavior and stress flow of suggested connection and to evaluate the resistance to shock of connection. Four T-type CFT column-to-beam specimens; two with combined cross diaphragm and the others with interior and through diaphragms, the existing connection types, were made for cyclic load test guided by the load program of ANSI/AISC SSPEC 2002. The results show that the proposed connection is more efficient than existing ones in terms of strength, stress flow and energy absorption and satisfies the seismic performance required in the region of weak/moderate earthquakes.

Key Words
concrete filled tube (CFT); combined cross diaphragm; column-to-beam connection; cyclic loading program.

Address
Sung-Mo Choi; School of Architecture and Architectural Engineering, University of Seoul, Seoul, 130-743, KorearnYeo-Sang Yun; Harmony Structural Engineering, Seoul, KorearnJin-Ho Kim; Research Institute of Indurstrial Science & Technology Steel Structure Research Laboratory,rnKyungkido, 445-813, Korea

Abstract
A rectangular plate made of a porous material is thernsubject of the work. Its mechanical properties varyrncontinuously on the thickness of a plate. Arnmathematical model of this plate, which bases onrnnonlinear displacement functions taking into accountrnshearing deformations, is presented. The assumedrndisplacement field, linear geometrical and physicalrnrelationships permit to describe the total potentialrnenergy of a plate. Using the principle ofrnstationarity of the total potential energy the set ofrnfive equilibrium equations for transversely and inrnplane loaded plates is obtained. The derivedrnequations are used for solving a problem of a bendingrnsimply supported plate loaded with transversernpressure. Moreover, the critical load of a bi-axiallyrnin-plane compressed plate is found. In both casesrninfluence of parameters on obtained solutions such asrna porosity coefficient or thickness ratio isrnanalysed. In order to compare analytical results arnfinite element model of a porous plate is built usingrnsystem ANSYS. Obtained numerical results are inrnagreement with analytical ones.

Key Words
non-homogeneous plate; elastic buckling; rectangular plate.

Address
K. Magnucki; Institute of Applied Mechanics, Poznan University of Technology, ul. Piotrowo 3, PL. 60-965 Poznan, PolandrnInstitute of Rail Vehicles \"TABOR\" ul. Warszawska 181, PL. 61-055 Poznan, PolandrnM. Malinowski; Institute of Mechanical Engineering and Machine Operation, University of Zielona Gora, Zielona Gora, PolandrnJ. Kasprzak; Institute of Applied Mechanics, Poznan University of Technology, Poznan, Poland

Abstract
The present paper hopes to elucidate the problem of determining if a given I-shaped cross-section is properly proportioned to accommodate sufficient plastic hinge rotation capacity to facilitate the redistribution of moments in a structural system as needed to accommodate the formation of a collapse mechanism. It might be tempting to believe that application of the limiting flange plate slenderness value for the case of major axis flexure are applicable in this case; since the pervasive belief is that this approach ought to be conservative. However, the present research study indicates that this is not the case and thus more sophisticated analysis techniques are required to better understand this case.

Key Words
compactness; minor axis bending; rotation capacity; finite element modelling; imperfection; weak axis bending.

Address
M. Aktas; Department of Civil Engineering, Sakarya University, Sakarya, TurkeyrnC. J. Earls; Department of Civil & Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, USA

Abstract
The discrete singular convolution (DSC) algorithm forrndetermining the frequencies of the free vibration ofrnsingle isotropic and orthotropic laminated conicalrnshells is developed by using a numerical solution ofrnthe governing differential equations of motion basedrnon Love\'s first approximation thin shell theory. Byrnapplying the discrete singular convolution method,rnthe free vibration equations of motion of therncomposite laminated conical shell are transformed torna set of algebraic equations. Convergence andrncomparison studies are carried out to check thernvalidity and accuracy of the DSC method. The obtainedrnresults are in excellent agreement with those in thernliterature.

Key Words
composite conical shells; free vibration; discrete singular convolution.

Address
Omer Civalek; Akdeniz University, Faculty of Engineering, Civil Engineering Department, Divisionrnof Mechanics, Antalya, Turkey


Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2017 Techno-Press
P.O. Box 33, Yuseong, Daejeon 34186 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: info@techno-press.com