The International Institute of Welding (IIW) has published its first comprehensive recommendation on fatigue design of welded structures in 1996. The document appeared in English, French, German and Japanese. The idea was to describe the fatigue properties of welded joints and components independently from application groups with their specific preferences and interests. So, a comprehensive code was established, which covered all current methods of verification, such as component testing, nominal stress, structural stress, notch stress method as well as fracture mechanics assessment procedures. Detailed guidance for assessment of weld imperfections was also given. The outlined safety philosophy covers the different strategies and provides a detailed choice for the designer. The document had a considerable impact on code making bodies and thus it became an important source for the Eurocode. After more than one decade, a new update of the IIW recommendations has been published. The main areas of update are firstly a new consideration of high cycle fatigue in the grid of the Woehler S-N curves, a standardized meshing for the structural hot-spot stress concept, which allows now an economic and coarser meshing in finite element analysis, further on the extension of the effective notch stress concept to welded aluminium structures, followed by a numerical assessment of post weld treatments for improving the fatigue properties, and finally a new approach to cumulative damage in connection with multi-axial stress. The update is a result of a worldwide collaboration of leading research institutions and it is expected that the new update will have the same impact on design and codes as the preceding document.

No short description available.

No short description available.

No short description available.

• European Steel Bridges Award
• Conferences
• Announcements
• Technical Commitee (TC) activities

No short description available.

• Sustainability strategy for the European steel construction sector
• Tata Steel opens processing centre to serve wind tower fabricators
• Jinso-pavilion Wins Dutch National Steel Prize 2010

No short description available.

No short description available.

No short description available.

It is clear that semi-rigid frames exhibit completely non-linear behaviour under cyclic loading due to gradual yielding of connection components. The current study presents the experimental results from the test of a semi-rigid frame specimen, comprising a single storey and one bay, and the analysis results obtained from a finite element model of the specimen. In this study, semi-rigid joints with header plates are used for beam-tocolumn connections. The initial stiffness and moment-carrying capacity of the connection, designed as a semi-rigid and partial strength connection type, were determined in accordance with Eurocode 3. In the modelling of the semi-rigid beam-to-column connection behaviour, four-parameter non-linear representation of the moment - rotation curve obtained using the Ramberg-Osgood formula was employed. Loading of the test specimen consisted of quasi-static cycles with displacement control. The cyclic response of the specimen is characterized by a stable hysteretic behaviour. When comparing the envelope of the hysteresis loops from the cyclic test of the specimen with the pushover curve achieved by non-linear finite element analysis, the model gives a good prediction of the ultimate strength and initial stiffness of the frame.

This paper discusses concepts and presents procedures for the development of a displacement-based seismic design methodology for chevron bracing. Both theoretically rigorous and simplified approximate methods for calculating frame displacements corresponding to significant limit states are proposed. In other words, analytical formulations are proposed for the calculation of inter-storey drift angles and associated displacements corresponding to brace buckling and the achievement of a given brace ductility demand. The aim of the displacement-based design (DBD) methodology developed is to control both elastic (pre-yield) and inelastic (post-yield) deformation modes, thus permitting control of damage distribution within the structure. The results gained from the application of the proposed methodology to a case study are then given. The structure designed was studied using dynamic time-history response analyses. The numerical results illustrate the good performance of the DBD-compliant structure which matches the performance objectives set at the design stage.

In current German and international standards for composite structures of steel and concrete, the determination of the ultimate load capacity and the fatigue life of headed shear studs is carried out with separate and independent verifications at the ultimate, serviceability and fatigue limit states. The fatigue resistance is verified in a similar way to steel structures, based on a nominal stresses concept and linear damage accumulation according to Palmgren-Miner. The effect of pre-damage due to fatigue loading at both the ultimate and serviceability limit states is not considered. Because cyclic loading of headed shear studs leads to a decrease in the static strength of stud connectors, the assumptions for independent limit states are not given and the reliability index of steel-concrete composite structures subjected to fatigue loading may fall below the target values in codes. This paper deals with the results of a comprehensive programme of experimental work with more than 90 standard EC4 push-out test specimens and two full-scale beam tests which consider the crack propagation through the stud foot and the local damage to the concrete surrounding the studs as relevant consequences of highcycle loading. Based on the results of the push-out tests, new design methods were developed to predict the fatigue life and the residual strength of headed shear studs after high-cycle loading. Considering the interaction between the local damage and the behaviour of the global structure, these research results were taken as the basis for simulating the cyclic behaviour of composite beams by means of a damage accumulation method.

This paper presents the outcome of an experimental study carried out by the authors on the performance of a connection between an I-beam and a square hollow section (SHS) column. In the light of practical and economic bolted field applications and transportation without damage by leaving the column exterior without projections, an appropriate joint type composed of T-stub connecting elements was studied. These connecting elements were bolted with long partially threaded studs passing through the SHS column. In order to observe the performance of the joint, four full-scale beam-column tee-joint specimens were tested under monotonic and cyclic loading in two groups. As a parameter, the rear face of the SHS column in the area of the connection was reinforced by backing plates in the second group of specimens. The results obtained are provided in terms of moment-rotation relationship and energy dissipation capacity. All specimens reached beam plastic load level at high deformation levels. Reinforcing the SHS column rear face with a backing plate resulted in an increase in strength and initial stiffness but a reduction in the energy dissipation capacity of the joint. Considering the overall cyclic performances, both joints maintained high plastic rotations in adequate resistance levels with acceptable energy dissipation capacities; consequently, they are suitable for use as semi-rigid partial strength joints in simply designed, braced steel frames in seismic regions or in unbraced steel frames in regions with less seismic activity. Additional component tests were carried out to understand better the component behaviour of the hollow section face in bending and to try to design component modelling parameters. The influence of bolt spacing and the distance between bolt rows on the resistance of the square hollow section face in bending was examined. As expected, when the bolts were closer to the sidewall, the resistance of the face increased.

In recent years, users, architects and engineers have all been searching for the most economic dwelling building systems. In this context, steel-framed houses have become a choice in many European countries, including Romania. One of the issues raised in the case of the new systems concerns their environmental impact. This paper presents an innovative structure/envelope solution, enabling flexible floor plans and modular construction, faster fabrication and erection times and high solution diversity for floors and envelope. The main features of the architectural and technical solution are presented here. In the second part, the paper presents a comparative life cycle analysis for the above house, designed with various solutions. For this purpose, the building was designed with four different solutions, each having its own structural system, as follows: (1) hot-rolled steel framing  -  the innovative structure; (2) cold-formed steel framing; (3) timber framing, and (4) masonry. Besides the life cycle analysis at the level of the structural framework, studies regarding the cladding solution, versatility and adaptability of the four structural frames have been integrated. Several aspects are presented in turn in order to underline the impact for different stages during the life cycle: (a) construction stage only; (b) construction stage and final disposal of materials; (c) construction stage, disposal and maintenance.

No short description available.

This paper describes a modular, easy-to-build, energy-efficient and affordable architectural concept for multi-storey residential buildings. The design concept evolves from a minimum modular grid that allows multiple combinations while ensuring spatial flexibility, net area optimization and adaptability. The proposed solution is based on light steel framing to allow easy erection and rapid construction without the need for complex and expensive in situ construction facilities.

This study aims to present the details of an earthquake-based refurbishment for the historical masonry of Beylerbeyi Palace, which has masonry walls and timber floors. Both the linear and non-linear analyses of the three-storey structure have proven that the timber floor system of the palace causes the structural masonry walls to displace independently and not transmit lateral earthquake loads. One solution to this problem that was tried was the replacement of the timber floor system by steel truss floors. On the other hand, the historical importance of the palace and the minimum intervention principle in the refurbishment of the cultural building stock meant that this strategy had to be limited to the roof of the palace. In doing so, an easy installation process, an undamaged historical fabric and a reversible strategy was expected. In this respect, four different applications of steel floor systems have been investigated for the roof of Beylerbeyi Palace.

No short description available.

Whereas the European column buckling curves are generally well accepted, the buckling curves given in Eurocode 3-1-1 for lateral-torsional (LT) and torsional-flexural (TF) buckling are still under discussion. This situation stems from the fact that the latter have not been developed with the same broad consensus as the column buckling curves, but had to be provided for the publication of the Eurocode in a rather short time. In the meantime, further research has achieved, on the one hand, a much deeper understanding of the mechanical behaviour and, on the other, a better approach for an appropriate design formulation for member buckling cases in conformity with the code. This paper reports on current developments in new design LT and TF buckling curves that are fully consistent with the background and methodology of the European column buckling curves.

No short description available.

STEELPROST  -  ”Innovative Fire Protective Coatings For Steel Structures“
Economics of Steel Framed Buildings in Europe (ESE)
National approval of Welding Coordinators

New Web Tools for ECCS Technical Committees (TCs)
TC6 (Fatigue and Fracture) activity
TC13 (Seismic Design) activity

Doc. Ing. Tomá Vraný, CSc. †
Wojciech Włodarczyk at 80
Werner Sobek awarded with Grande Médaille d’Argent pour Recherche et Technique by French Académie d’Architecture

No short description available.