Time filter

Source Type

La Ferté-Saint-Aubin, France

Vassart O.,ArcelorMittal | Bailey C.G.,University of Manchester | Hawes M.,ASD Westok Ltd. | Nadjai A.,University of Ulster | And 4 more authors.
Journal of Structural Fire Engineering | Year: 2011

This paper describes a full scale fire test performed the 27th of February 2010 on a composite floor for analysing the possibility of tensile membrane action to develop when the unprotected steel beams in the central part of the floor are made of cellular beams. The natural fire was created by a wood crib fire load of 700 MJ/m2 and the 9 × 15 m floor survived the fire that peaked at 1000°C and lasted for 90 minutes. Blind predictions of the air temperature development by the software OZone and of the structural behaviour by the software SAFIR which proved quite satisfactory are also described. Source

The fatigue behaviour of aluminium shows not only many similarities, but also some differences with the fatigue behaviour of steel. There exist separate Eurocodes for the fatigue design of steel and of aluminium structures, EN1993-1-9 and EN1999-1-3, respectively. The latter standard was developed after the draft version of the first one was available. However, a number of aspects are considered in a different way in the two standards. Are these differences justified and desired? What can we learn from the two standards for future improvement of the documents? This paper presents and discusses the agreements and differences between the two Eurocodes. The paper evaluates the advantages and disadvantages of the approaches adopted in one or another of the two standards. It may serve as a starting point for future harmonization of the two standards. © 2013 The Authors. Published by Elsevier Ltd. Source

Kanyilmaz A.,Polytechnic of Milan | Castiglioni C.A.,Polytechnic of Milan | Degee H.,Hasselt University | Martin P.-O.,CTICM
COMPDYN 2015 - 5th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering | Year: 2015

Concentrically braced frames (CBF) represent a very effective structural form against horizontal loading. They provide high lateral resistance at the same time limiting lateral displacements. Thanks to their simpler connection details and smaller cross sections, they are economic alternatives to the costly moment resisting frames. Nevertheless, concerning the seismic design, current Eurocode 8 provisions require a quite high level of complexity for the dissipative design of CBF structures. The global aim of this research is to find an optimal balance between safety and economy for the design of CBF structures, located in low-to-moderate seismic regions. New design rules will be proposed which will have less stringent local ductility and structural homogeneity requirements than current medium ductility class (DCM), and provide necessary safety level limiting the complexity and costs associated with anti-seismic design. This paper presents the results of the preliminary numerical analysis that has been realized thanks to the research fund received from European commission with the contract MEAKADO RFSR-CT-2013-00022. Source

Pak D.,RWTH Aachen | Hechler O.,ArcelorMittal | Martin P.-O.,CTICM
Structural Engineering International: Journal of the International Association for Bridge and Structural Engineering (IABSE) | Year: 2011

Integral abutment bridges (IABs) are an economical option to design appealing single-span bridges. However, more experience is needed, as the main difference in the design of IAB compared with conventional bridges is the restraint of the frame corner, caused by the fact that the supe rstructure and the abutments are one monolithic structure. This requires modification in design regarding the internal forces and deformations as well as the detailing of the frame corner itself. IABs are generally designed as frames us ing grid models with idealised superstructure. This calculation involves sophisticated models and is considered to be time consuming. Also conventional single-spa n bridges are designed with the help of grid models, for which experience and various design software tools exist, especially when simply supported structures are considered. Main problem in the transfer of frame systems into simply supported structures are the interactions between superstructure and sub-structure. By separating the superstructure from the sub-structure, the implementation of IAB design through existing software tools is possible. However, to take into account the superstructure- abutment interaction, the superstructure needs to be restrained by rotational springs. As a result of sway effects in the original frame, the boundary conditions (horizontal position of the frame corner) for the determination of the rotational spring stiffness vary. Therefore these springs have to be non-linear, and do not comply with the demand for load case superposition. This paper presents a new approach to separate the superstructure from the sub-structure with p rovision for possible superposition of the load cases. The approach is based on the division of the non-linear springs into two linear springs, one for symmetric loading and the other for antimetric loading, from which a modification factor kmgk has been derived. This factor is defined as adjusting the single-span model with a single rotational linear spring to the original grid model system. On the basis of this approach and the kmgk factor, the use of conventional design tools for IABs has been made possible. To further close the gap in experience on IAB, design and detailing recommendations are given. Source

Nadjai A.,University of Ulster | Bailey C.G.,University of Manchester | Vassart O.,ArcelorMittal | Han S.,University of Ulster | And 4 more authors.
Structural Engineer | Year: 2011

As part of an international major research initiative, dealing with the behaviour of long span cellular beams in steel framed buildings under fire, a large-scale fire test incorporating 15m long cellular beams was carried out. The test incorporated unprotected secondary cellular steel beams acting compositely with the supporting floor slab. The floorplate in its entirety was designed to carry the load with unprotected beams, when subjected to a severe fire, by utilising membrane action of the floor slab. The overall structure performed very well supporting the full applied static load for the duration of the test. The unprotected cellular steel beams were subjected to distortional buckling, with only the top tee providing any support through catanary action. The test supported the assumptions adopted in the structural design approach and provided an accurate estimate of the strength of the floorplate. Comparison of the recorded time-temperature relationship of the fire with the design method presented in the Eurocodes shows that the code under-predicts the severity of the fire, although this was compensated to some extent by the conservative assumptions embedded within the structural model. Source

Discover hidden collaborations