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Investigation of an engineering model for the assessment of the seismic behaviour of large mobile equipment For large mobile equipment in seismically active regions, seismic stability is an essential and often decisive design criterion. The seismic behaviour of such large equipment is usually characterised by complex nonlinear types of behaviour (uplift, tilting and rocking), which are difficult to compute and analyse in practice. In this paper, a highly simplified engineering model is presented or developed step by step, which should be able to represent basic features of the typical behaviour of large mobile equipment transverse to the rail under seismic excitation. The typical rocking motion of the equipment, as determined in previous analyses, is to be reflected in the simplified model. The engineering model will be designed in such a way that it is able to reproduce qualitative statements about uplift and rocking or tilting as a function of incisive model parameters and seismic excitation. The dissipation mechanisms of the model are presented and seismic tilting spectra are generated using different approaches. The suitability and applicability of these approaches for assessing uplift and rocking tendencies for large mobile equipment is reviewed using representative series of bucket wheel machines and stackers as examples. In addition, parameters are determined for quantitative application to further large mobile equipment and the delimitation criteria of qualitative and quantitative applicability are compiled. [ABSTRACT FROM AUTHOR]

Determining the overstrengthfactor based on statistical values of European steel grades In dissipative seismic design concepts, capacity design rules have to be applied to control the plastic mechanism. For this purpose, non‐dissipative structural elements require an overstrength in respect to dissipative regions. Scattering of the yield strength of structural steel is considered in DIN EN 1998‐1 by the material overstrength factor γov with a recommended value of 1.25. However, current measurement data show often significant higher yield strength especially for steel grades with low nominal strengths. In this article, new yield strength data of European steel grades are evaluated and compared with statistical values from literature. Based on a new probabilistic model for the yield strength a steel grade‐dependent overstrength factor is proposed, which is also implemented in the new German National Annex DIN EN 1998‐1/NA:2018. [ABSTRACT FROM AUTHOR]

Abstract: Failure of a steel pallet rack in Athens. Pallet racking systems have peculiar characteristics which differ from usual steel structures that make them sensitive to stability failure modes. In the present paper a rack failure is presented where the rack has failed due to lateral torsional and distortional buckling of its most stressed uprights. The structural behavior was studied by a combination of experimental and numerical/analytical methods. The investigations included test loading, bending tests on pallet beams, compression tests on stub column and bending tests on beam end connectors. Subsequently, a global geometrical non‐linear analysis is performed on the 3‐D system. Its results indicate by comparison with the pictures of the actual structure that the collapse mode is correctly detected. Conclusions are drawn that recommend the performance of static and dynamic analyses on an obligatory basis. [ABSTRACT FROM AUTHOR]

Am Flughafen Baku in Aserbaidschan wurde das neue Terminalgebäude für den Flugbetrieb eröffnet. Dieses gemeinsam mit einem internationalen Team von Planern entwickelte Projekt zeigt bespielhaft die Herausforderungen beim Bauen in der Region. Im folgenden Artikel wird der Prozess von der Geometriebeschreibung über die Entwicklung des Tragwerkskonzeptes unter besonderer Berücksichtigung der Erdbebenbeanspruchung sowie deren Auswirkung auf das Toleranzkonzept der Gebäudehülle skizziert. Weiterhin wird auf die Besonderheiten der Fertigungsprozesse sowie auf die Anforderungen an die Montageabläufe näher eingegangen, die es im Zuge der Realisierung dieser anspruchsvollen Geometrie des Terminals als Stahl-Glas-Struktur zu berücksichtigen gab. Gateway to Baku - The steel and glass building envelope of the new airport terminal in Azerbaijan. The new terminal building was opened at the Baku airport (Azerbaijan) for flight operations. Developed in collaboration with an international team of planners project shows the challenges that need to be tackled when building in the region. The present article presents the development process for the geometry and the structural concept, with special emphasis on the severity of the seismic load and its consequences on the design of the tolerance concept for the building envelope. Furthermore, a presentation is made of the particularities of the complex fabrication and installation processes that made the realization of such a challenging geometry out of a steel-glass structure possible. [ABSTRACT FROM AUTHOR]

The problem of the progressive collapse of structures is today at the forefront of structural engineering because of multiple natural and man-made hazards, the aging of the infrastructure and the catastrophic consequences associated with that. This paper investigates the effects of different strengthening techniques for mitigating the phenomenon of progressive collapse for 2D steel moment frames. These techniques are applied to a series of moment frames of varying heights and designs using a finite element analysis involving both material and geometric non-linearities. The results of this work demonstrate that, when analysed as 2D assemblies, realistic, similar steel frame structures undergo different collapse mechanisms and that a general strengthening scheme cannot be applied to all collapse mechanisms. Verhinderung des fortschreitenden Versagens von zweidimensionalen biegesteifen Stahlrahmen - Bewertung der Wirksamkeit unterschiedlicher Verstärkungsmaßnahmen. Das Problem fortschreitenden Versagens von Konstruktionen steht heute im Mittelpunkt des Ingenieurhochbaus. Gründe dafür sind verschiedene durch Mensch und Natur verursachte Unfälle, die alternde Infrastruktur und die damit verbundenen katastrophalen Folgen. Im vorliegenden Beitrag wird die Wirksamkeit unterschiedlicher Verstärkungsmaßnahmen zur Verhinderung des fortschreitenden Versagens bei zweidimensionalen biegesteifen Stahlrahmen untersucht. Die Verstärkungsmaßnahmen werden für eine Reihe von biegesteifen Stahlrahmen unterschiedlicher Höhe und Ausführung betrachtet. Dazu wird die Finite-Elemente-Methode unter Berücksichtigung von materiellen und geometrischen Nichtlinearitäten verwendet. Die Untersuchungsergebnisse zeigen, dass reale, vergleichbare Stahlrahmen-Konstruktionen, die als zweidimensionale Baugruppen analysiert wurden, unterschiedlichen Versagensmechanismen unterworfen sind und dass eine allgemeine Verstärkungsmaßnahme nicht für alle Versagensmechanismen angewendet werden kann. [ABSTRACT FROM AUTHOR]