Tests on iron materials

Report (2008)

Development of design rules for iron columns reinforced by FRP

Report (2008)

In the available literature, some techniques of reinforcement are proposed: reinforcement with the use of cables, replacement of damage elements, creation of a composite action by connecting the damage ... [more ▼]

In the available literature, some techniques of reinforcement are proposed: reinforcement with the use of cables, replacement of damage elements, creation of a composite action by connecting the damage elements to a concrete slab, etc; but few of them are applicable to the Umberto 1 gallery. The one that seems to be applicable is the FRP (Fibre Reinforcement Polymer) technique. The behaviour of composite elements composed of FRP and steel members under tension seems to be known, but little information is available as far as the behaviour of such elements in compression. Following the "Iron meeting" held in Naples on June 8th, 2006, tests on stocky elements with and without FRP are planned to be performed in tension and in compression to identify the effect of FRP on such elements. In addition, tests on slender columns will be performed with and without FRP to investigate the influence of the latter on the buckling resistance. All the tests will be accompanied by coupon tests to identify the mechanical properties of the constitutive material of the tested specimens (Liège contribution to WP7). Based on the test campaign, analytical design rules founded on an elastic approach have been developed for the computation of the resistance of iron columns reinforced by FRP; these rules are detailed in the present section and reflect the contribution of the University of Liège to WP9. [less ▲]

Iron columns reinforced by FRP under axial compression

Report (2008)

Slender iron column reinforced by FRP is sensitive to buckling phenomenon, taking place obviously at a cross-section within the middle segment. An equivalent FRP-iron cross-section can be used to derive ... [more ▼]

Slender iron column reinforced by FRP is sensitive to buckling phenomenon, taking place obviously at a cross-section within the middle segment. An equivalent FRP-iron cross-section can be used to derive the buckling resistance of the composite member by using buckling formulation previously defined for column members. [less ▲]

Recent developments on composite connections

in Steel Construction - Design and Research Journal (2008), 1

Robust structures by joint ductility

Report (2008)

In view of recent disasters and their immense economical and human consequences more and more focus is given not only on the safety of structures - to reduce the risk for the life of people by collapse ... [more ▼]

In view of recent disasters and their immense economical and human consequences more and more focus is given not only on the safety of structures - to reduce the risk for the life of people by collapse even under exceptional loading – but on minimizing the disastrous results and to enable a quick rebuilding and reuse. One crucial mean to achieve this aim is the design of redundant robust structures. Robustness prevents the collapse of the total structure when only parts of the structure are damaged or destroyed. To avoid progressive failure, redundant structures with inherent sufficient ductile behaviour allowing deformations when a local failure occurs, have to be built. Redundancy can be achieved by allowing force redistribution within a structural system. Therefore the single sections and joints have to be especially designed and optimized, not necessarily requiring additional fabrication costs. But until now no specific rules for robustness by ductile joints exist. The aim of the present project is to define general requirements for ductile joints as part of a structural system subjected to exceptional unforeseen loading. [less ▲]

Experimental investigations on the behaviour of a composite frame after the loss of a column

in Beale, R. G. (Ed.) Proceeding of the 6th International Conference on Steel and Aluminium Structures (2007, July 24)

Recent events such as natural catastrophes or terrorism attacks have highlighted the necessity to ensure the structural integrity of buildings under exceptional loading, i.e. other accidental loads than ... [more ▼]

Recent events such as natural catastrophes or terrorism attacks have highlighted the necessity to ensure the structural integrity of buildings under exceptional loading, i.e. other accidental loads than those already taken into consideration in the design process. According to Eurocodes and some other national design codes, the structural integrity of civil engineering structures should be ensured through appropriate measures but, in most of the cases, no precise practical guidelines on how to achieve this goal are provided. Even basic requirements to fulfil are generally not clearly expressed. An European RFCS project called “Robust structures by joint ductility” has been set up in 2004, for three years, with the aim to provide requirements and practical guidelines allowing to ensure the structural integrity of steel and composite structures under exceptional loading through an appropriate robustness. This project involves analytical, numerical and experimental investigations; in particular, one substructure test simulating the loss of a column in a composite building, because of an unexpected impact, was performed in September 2006 at the University of Liège. This paper describes the experimental test carried out at the University of Liège, as part of this European project, and the first interpretation of the results. [less ▲]

Eurocode 4 EN 1994: Exemples d'application au calcul des structures mixtes acier - béton

in Jaspart, Jean-Pierre; Maquoi, René; Demonceau, Jean-François (Eds.) et al Eurocode 4 EN 1994: Exemples d'application au calcul des structures mixtes acier - béton (2007)

Elements de construction mixte

Learning material (2006)

Design of composite sway building frames for global instability

in Journal of Engineering Mechanics (2005), 131(6), 641-653

Eurocode 4 is the European design code for composite construction; in its so-called ENV version, the scope is limited to "nonsway buildings" with efficient bracing systems. Therefore, it gives mainly ... [more ▼]

Eurocode 4 is the European design code for composite construction; in its so-called ENV version, the scope is limited to "nonsway buildings" with efficient bracing systems. Therefore, it gives mainly rules to analyze and to check structural elements like beams, columns, slabs, and joints. However, in the last years, the construction of taller buildings and larger industrial halls without wind bracing systems is susceptible to make global instability a relevant failure mode, which is not covered by Eurocode 4. For 3 years, in the framework of a European research project funded by the European Community for Steel and Coal, in which the Univ. of Liege was deeply involved, intensive experimental, numerical, and theoretical investigations have been carried out. The latter aimed at improving the knowledge in the field of sway composite frames and at developing appropriate design rules. The rotational behavior of the beam-to-column composite joints is one of the key aspects of the problem to which special attention has been paid. This paper presents the numerical and analytical studies carried out at Liege Univ., as part of above European project, with the objective to investigate the behavior of sway composite structures under static loading. Particular phenomena put into sight through different analyses are illustrated herein. The actual response of the beam-to-column composite joints may be easily integrated into the described design and analysis procedures; this specific aspect is therefore not addressed in the paper. [less ▲]

Contribution to the design of sway composite frames

in Leon, Roberto; Lange, Jörg (Eds.) Composite Construction in Steel and Concrete V (2004, July 18)

This paper presents numerical and analytical studies carried out at Liège University, as part of a European research project, with the objective to investigate the in-plane behaviour of composite sway ... [more ▼]

This paper presents numerical and analytical studies carried out at Liège University, as part of a European research project, with the objective to investigate the in-plane behaviour of composite sway frames under static loading. [less ▲]