Gerhard Sedlacek

New design rules for plated structures in Eurocode 3

Abstract This paper gives an overview of Eurocode 3 Part 1.5 Design of Steel Structures. Supplementary rules for planar plated structures without transverse loading have been developed together with the Eurocode 3-2 Steel bridges. It covers stiffened and unstiffened plates in common steel bridges and similar structures. This paper presents the background and justification of some of the design rules with focus on the ultimate limit states. The design rules for buckling of stiffened plates loaded by direct stress are presented and explained. For shear resistance and patch loading the new rules are briefly derived and compared with the rules in Eurocode 3-1-1. Finally, the statistical calibration of the rules to tests is described.

A simplified method for the determination of the effective width due to shear lag effects

Abstract While it is usually assumed in bending theory that plane sections remain plane after loading, this assumption does not hold for short span beams with wide flanges. Shear lag effects cause the stress distribution over the cross-section to be non-linear. This paper presents simplified formulae, which relate the effective flange widths to the significant parameters. The solution is restricted to the bending problem by assuming that twisting and warping effects can be neglected. The accuracy of the method presented is only slightly affected by the approximations introduced. Rules suitable for code applications are derived and proposed for the unification of the national and international code specifications.

Durability of asphaltic pavements on orthotropic decks of steel bridges

Abstract By using a simplified model for calculating the action effects in asphaltic pavements on orthotropic decks of steel bridges and by comparing the results with data from inspection reports, it has been possible to define the ultimate resistance of these pavements. From this, the minimum stiffness requirement for the stringers of orthotropic decks in the draft of German steel road-bridge code DIN 18809 is derived. Results of theoretical studies on the material behaviour of the asphaltic pavements are reported. These can be used to identify areas of improvement for the mechanical properties of asphaltic pavements on orthotropic steel bridge decks.

Design philosophy of Eurocodes — background information

Abstract ENV 1993-1.4 — Supplementary rules for stainless steels — may be used as a complementary part to Eurocode 3 Part 1.1 — General rules and rules for buildings — to design structural elements made of stainless steel. The rules specified in ENV 1993-1.4 are based on the design rules for carbon steels although the stress–strain curves for austenitic stainless steels do not exhibit a distinct yielding plateau. The particular material behaviour of stainless steels affects the design rules; however, in drafting ENV 1993-1.4, very conservative rules were adopted owing to the fact that experimental evidence was not available to justify more favourable rules. This paper deals with the base design philosophy of Eurocodes, points out some relevant differences between designing with carbon steels and austenitic stainless steels related to this philosophy, and presents further test results.

Bridge Design to Eurocodes – Worked examples

This document is a Technical Report with worked examples for a bridge structure designed following the Eurocodes. It summarizes important points of the Eurocodes for the design of concrete, steel and composite road bridges, including foundations and seismic design, utilizing a common bridge project as a basis. The geometry and materials of the example bridge as well as the main assumptions and the detailed structural calculations are presented in the first chapter of the report. Each of the subsequent chapters presents the main principles and rules of a specific Eurocode and their application on the example bridge, namely: • The key concepts of basis of design, i.e. design situations, limit states, the single source principle and the combinations of actions (EN 19990); • Permanent, wind, thermal, traffic and fatigue actions on the bridge deck and piers and their combinations (EN 1991); • Bridge deck modeling and structural analysis; • The design of the bridge deck and the piers for the ULS and the SLS, including the second-order effects (EN 1992-2); • The classification of the composite cross-sections, the ULS, SLS and fatigue verifications and the detailed design for creep and shrinkage (EN 1994-2); • The settlement and resistance calculations for the pier, three design approaches for the abutment and the verification of the foundation for the seismic design situation (EN 1997); • The conceptual design for earthquake resistance considering the alternative solutions of slender or squat piers; the latter case involves seismic isolation and design for ductile behavior (EN 1998-1, EN 1998-2). The bridge worked example analyzed in this report was prepared and presented at the workshop “Bridge Design to the Eurocodes” that was held on 4-6 October 2010 in Vienna, Austria. The workshop was organized by JRC with the support of DG ENTR and in collaboration with CEN/TC250/Horizontal Group Bridges, the Austrian Federal Ministry for Transport, Innovation and Technology and the Austrian Standards Institute. The document is part of the Report Series “Support to the implementation, harmonization and further development of the Eurocodes”, prepared by JRC in collaboration with DG ENTR and CEN/TC250 “Structural Eurocodes”. Files: reqno_jrc68415_bridge_design_to_eurocodes_-_worked_examples_-_lbna25193enn[1].pdf [1] URI: Authors: BOUASSIDA Yorsa BOUCHON Emmanuel CRESPO Pilar CROCE Pietro DAVAINE Laurence DENTON Steve FELDMANN Markus FRANK Roger HANSWILLE Gerhard HENSEN Wolfang KOLIAS Basil MALAKATAS Nikolaos MANCINI Giuseppe ORTEGA CORNEJO Miguel SEDLACEK Gerhard TSIONIS Georgios ATHANASOPOULOU Adamantia POLJANSEK Martin PINTO VIEIRA Artur Publication Year: 2012 Type: EUR Scientific and Technical Research Reports

Safety considerations of annex j of eurocode 3

Publisher Summary The new Annex J of ENV 1993 -Eurocode 3 presents rules for the design of joints both for stiffness and strength. Due to the different components and materials of which a joint may exist, the safety assessment of structural joints is complex. This chapter provides considerations of the influence of unexpected over strength on the ductility and safety of joints. For seismic loading a method is suggested, which allows an extension of plastic design to joints with alternating rotations. Furthermore, the ULS-design of a steel structure consisting of elements and joints may be performed with two options. The first option is the consideration of the whole true moment-rotation characteristic of the joints. The second option is the use of a standardized model, which describes the moment rotation behavior of a joint in a simplified way: the initial stiffness, the transition from the elastic part to the plastic part of the curve and the ultimate resistance level without an a priori limitation of the rotation.

Konstruktiver Ingenieurbau und Hochbau

Holz besteht aus Zellen unterschiedlichster Art, Grose und Form. Gleichartige Zellen sind zu Verbanden, den sog. „Geweben“, zusammengefasst. Im Hinblick auf ihre Funktion konnen drei Gewebearten unterschieden werden: Festigungsgewebe, Leitgewebe und Speichergewebe. Beim entwicklungsgeschichtlich alteren und daher einfacher aufgebauten Nadelholz ubernehmen manche Zellen gleichzeitig mehrere Funktionen. Das auf einer hoheren Entwicklungsstufe stehende Laubholz ist durch eine grosere Vielfalt an Zellarten, die jeweils nur eine Funktion ausuben, gekennzeichnet. Bei Nadelholzern besteht das Festigungsgewebe aus den Tracheiden, die auch das Wasser leiten, bei Laubholzern aus den Libriformfasern und den Fasertracheiden. Im Laubholz wird das Wasser v. a. durch die Gefase geleitet, die im Querschnitt auch als Poren bezeichnet werden. Sie besitzen im Vergleich zu anderen Zellen einen sehr viel groβeren Durchmesser und groβe Gefaβe sind haufig schon mit bloβem Auge zu erkennen. Die Holzzellen verlaufen ganz uberwiegend in Stammrichtung. Die wenigen quer dazu verlaufenden Zellen bilden die Holzstrahlen.

Investigations on Beams with Multiple Regular Web Openings

In recent years the application of cellular beams is more and more requested by architects and designers. Not only their aesthetical appearance as visible steel structures and economic design are popular, also the possibility to pass service integrations through the openings is given. In the scope of the ECSC project 7210-PR-315 Large web openings for service integration in composite floors the performance of beams with web openings was studied experimentally and theoretically. The aim of this paper is to present the investigation on beams with multiple regular web openings with special focus on different failure mechanisms. The test program comprehended large scale tests with the following objectives: (1) Composite action close to support, (2) Behavior of elongated openings, (3) Load introduction via secondary beams, (4) Asymmetric design, and (5) Stiffening of web openings. On the basis of the test results and theoretical investigations including numerical simulations, design recommendations were established.

The design of steel structures according to Eurocode 8

Abstract This paper describes briefly the aims and structure of Eurocode 8, as well as the general procedure for the application of the code for the design of steel structures in seismic regions. In particular, rules for ensuring the dissipative behaviour and sufficient regularity of structures are described. The basic design criteria and detailed rules for steel structures are also mentioned.