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


scs
 
CONTENTS
Volume 3, Number 5, October 2003
 

Abstract
This paper presents an efficient approach to the determination of the buckling loads of downaisle, spliced, unbraced, pallet rack structures subjected to vertical and horizontal loads. A pallet rack structures is analysed by considering the stability equations of an equivalent free-sway column. The effects of semi-rigid beam-to-upright, splice-to-upright and base-plate-to-upright connections are fully incorporated into the analysis. Each section of upright between successive beam levels in the pallet rack is considered to be a single column element with two rotational degrees of freedom. A computer algebra package was used to determine modified stability equations for column elements containing splices. The influence of the position of splices in a pallet rack is clearly demonstrated.rn

Key Words
cold-formed steel; pallet racks; design; stability; buckling

Address
Slender Structures Research Group, OCSLD Technology,rnOxford Brookes University, Gipsy Lane, Headington, Oxford, UKrn

Abstract
The paper presents the results of an experimental investigation conducted on welded tubular joints, that are employed in offshore platforms, to study the behaviour and strength of these joints under axial brace compression loading. The geometrical configuration of the joints tested were T and Y. The nominal diameter of the chord and brace members of the joint were 324 and 219 mm respectively. The chord thickness was 12 mm and the brace 8 mm. The tested joints are approximately quarter size when compared to the largest joints in the platforms built in a shallow water depth of 80 m in the Bombay High field. Some of the joints were actually fabricated by a leading offshore agency which firm is directly involved in the fabrication of prototype structures. Strength of the internally ring-stiffened joints was found to be almost twice that of the unstiffened joints of the same configuration and dimensions. Bending of the chord as a whole was observed to be the predominant mode of deformation of the internally ring-stiffened joints in contrast to ovaling and punching shear of the unstiffened joints. It was observed in this investigation that unstiffened joint was stiffer in ovaling mode than in bending and that midspan deflection of unstiffened joint was insignificant when compared to that of the internally ring stiffened joint. The measured midspan deflection of the unstiffened joint in this investigation and its relation with the applied axial load compares very well with that predicted for the brace axial displacement by energy method published in the literature. A comparison of the measured deflection and ovaling of the unstiffened joint was made with that published by the author elsewhere in which numerical prediction of both quantities have been made using ANSYS software package. The agreement was found to be quite good.rn

Key Words
offshore platforms; tubular joints; internally ring-stiffened; unstiffened; testing; behaviour; strength

Address
Shock and Vibration Laboratory, Structural Engineering Research Centre,rnCSIR Campus, Tharamani, Chennai 600 113, Tamil Nadu, Indiarn

Abstract
The behaviour of composite frame - shear wall systems with regard to creep and shrinkage with high beam stiffness has been largely unattended until recently since no procedure has been available. Recently an accurate procedure, termed the Consistent Procedure (CP), has been developed which is applicable for low as well as for high beam stiffness. In this paper, CP is adapted for a class of composite frame - shear wall systems comprising of steel columns and R.C. shear walls. Studies are reported for the composite systems with high as well as low beam stiffness. It is shown that considerable load redistribution occurs between the R.C. shear wall and the steel columns and additional moments occur in beams. The magnitude of the load redistribution and the additional moment in the beams depend on the stiffness of the beams. It is also shown that the effect of creep and shrinkage are greater for the composite frame - shear wall system than for the equivalent R.C. frame - shear wall system.rn

Key Words
tall building; creep; shrinkage; composite frame - shear wall system; R.C. frame - shear wall system; beam stiffness

Address
Department of Civil Engineering, Indian Institute of Technology, Delhi, Hauz Khas,rnNew Delhi 110016, IndiarnDepartment of Civil Engineering, Engineering College, Ujjain, Madhya Pradesh, IndiarnDepartment of Civil Engineering, Indian Institute of Technology, Delhi, Hauz Khas,rnNew Delhi 110016, Indiarn

Abstract
The paper concerns the modelling of rigid and semi-rigid steel-concrete composite joints under monotonic loading through use of the Abaqus program, a widespread finite element code. By comparing numerical and experimental results obtained on cruciform tests, it is shown that the proposed modelling allows a good fit of the global joint response in terms of moment-rotation law. Even the local response in terms of stresses and strains is adequately predicted. Hence, this numerical approach may represent a useful tool for attaining a better understanding of experimental results. It may also be used to perform parametric analyses and to calibrate simplified mechanical models for practical applications. rn

Key Words
Abaqus code; beam-to-column connection; finite element modelling; non-linear analysis; semi-rigid joints; steel-concrete composite joints

Address
Department of Civil Engineering, University of Trieste, Piazzale Europa 1, rn34127 Trieste, Italyrn

Abstract
This paper analyses the response of rigid and semi-rigid steel-concrete composite joints under monotonic loading. The influence of some important parameters, such as the presence of column web stiffening and the mechanical properties of component materials, is investigated by using a three-dimensional finite element modelling based on the Abaqus code. Numerical and experimental responses of different types of composite joints are also compared with the analytical results obtained using the component approach proposed by Eurocode 4. The results obtained with this approach generally fit well with the numerical and experimental values in terms of strength. Conversely, some significant limits arise when evaluating initial stiffness and non-linear behaviour of the composite joint.rn

Key Words
Abaqus code; beam-to-column connection; Eurocode 4; semi-rigid joints; steel-concrete composite joints

Address
Department of Civil Engineering, University of Trieste, Piazzale Europa 1, 34127 Trieste, Italyrn


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