Diverse process openings have to be provided in the bottom parts of cylindrical tanks for the storage of liquids. Pipelines have to be connected to each tank product. These are mostly 700 mm in diameter in the case of tanks with a capacity of 50 000 m3 and more. An opening in the tank shell for a pipeline of such a diameter weakens the shell significantly. Furthermore, this occurs in the region where the material is exposed to the greatest stresses  -  in the zone of boundary disturbances at the junction between the cylindrical shell and the bottom plate.
In the shells of tanks for the storage of crude oil, a large opening in the form of a rectangle, joined at the top to a half-ellipse, have to be formed in the same zone of boundary disturbances, directly at the shell/bottom junction. Very often such openings are more than 900 mm high, and they can be up to 1500 mm wide (depending on tank capacity). The opening is required for a so-called cleanout door, designed for the removal of deposits precipitating from crude oil and lying on the tank bottom. To be effective during the cleaning of a tank, such clean-out doors should have their lower edge flush with the tank bottom. That causes a large change of stresses in the zone of boundary disturbances both in the shell and in the tank bottom. For that reason, both of these structural components have to be significantly strengthened in the proximity of the clean-out door.
This paper is concerned with the analysis of stresses in the region of strengthening at both the aforementioned openings in the tank shell. Since the nature of stress changes  -  and therefore also the strengthening around these openings  -  is different, this paper has been divided into two parts, each of them having a separate introduction and presenting separate conclusions. Those conclusions are fit for practical applications.

As consumption of energy in the world is rising, there is growing interest in the building of pressure vessels as well as apparatus engineering and equipment construction for the storage of gases or technical liquids. For these applications, like boilers, reactors and columns, unalloyed or Nb-microalloyed steels with a minimum yield strength of up to 460 MPa have been used and produced as heavy plates according to rules and international standards and specifications (i.e. DIN EN 10028, ASTM, ASME).
The production and properties of modern steels for welded pressure vessels, which meet the actual requirements very well, are discussed here. In this respect, thanks to specific secondary metallurgy during steelmaking, targeted Nb-microalloying, innovative rolling strategies and (if necessary) optimized heat treatment conditions, it is possible to produce a fine-grained microstructure in order to cover the highest material property requirements, in particular toughness and resistance to brittle failure. Multiple certifications of different steel grades according to different specifications for plates made from pressure vessel steels are common practice. Additionally, important aspects regarding the processing behaviour of modern steels for pressure vessels are stress-relief heat treatment and welding. Here, modern pressure vessel steels meet the highest demands for a practice-oriented processing of plates.

Wind turbines are designed and certified for a period of 20 years. The turbines of the first generation have now reached that age. What is going to happen to these wind turbines? Do they measure up to the most up-to-date technology? Can they continue to be operated or do they have to be scrapped? The publication of the internationally valid “Guideline for the Continued Operation of Wind Turbines” by Germanischer Lloyd offers owners and operators of wind turbines, insurance companies, creditors, manufacturers and building authorities support in answering these questions. This article provides an introduction to the background and content of the new “Guideline for the Continued Operation of Wind Turbines” and concludes with a brief look at the prospects and the latest experiences of Germanischer Lloyd since the publication of the Guideline.

• Minoru Yamada at 80
• Holger Svensson reaches 65

• Composite bridges with integral abutments
• 11th International Conference on Applications of Statistics and Proba bility in Civil Engineering
• 13th International Symposium on Tubular Structures
• 6th European Conference on Steel and Composite Structures

No short description available.

No short description available.

No short description available.

This paper will give a brief introduction to EN 1990, describe many of its innovative features and plans for the medium- to long-term development of the code. Prof. Sedlacek has consistently been a major contributor to its development.

No short description available.

EN 1993-1-5 provides harmonized European design rules for plated structures. It is a step forward in the harmonization process, but like all the Eurocodes it includes many options for national choices, in terms of parameters and also methods, which leads to quite different results. Actually, there are four different methods for dealing with buckling problems. One purpose of this paper is to illustrate differences by way of examples and also to suggest topics for studies intended to improve the design rules and bring them closer together. The revision of EN 1993-1-5 is due to take place around 2014 and there is ample time for performing research projects that can form the basis for the new version. Examples of such topics are the recalibration of buckling curves, reviewing the interaction checks and the verification format of the reduced stress method.

Reinforced concrete constructions represent the largest part of the built heritage in the Euro-Mediterranean region because they characterize the related principal way of construction during the 20th Century. The widespread high seismic vulnerability of such constructions is mainly due to the fact that, primarily in the case of structures erected more than 20 years ago, they are usually designed to resist gravitational loads only. Hence, the possibility of resisting horizontal actions, e.g. seismic, is essentially due to overstrength effects. Considering the enormous diffusion of reinforced concrete constructions designed for vertical loads only, in recent years we have seen a growing interest in the establishment and development of innovative seismic protection systems able to improve the seismic behaviour of such constructions and also retain their original structural features. This paper describes the use of metallic bracing systems for the seismic retrofitting of reinforced concrete buildings designed for vertical loads only. Both the experimental and numerical results of the studies carried out on these systems within the scope of the ILVA-IDEM Italian research project and the PROHITEH EC-funded project are shown.

Innovative concepts for beam-to-column joints are currently under development. The emphasis with these new forms is on providing an incentive for the mass production of joints and connections, automating the process of structural assembly and reducing dangerous erection procedures. Two alternative concepts for moment-transmitting joints are addressed below. The joints include modular connecting elements that provide stability during the erection phase and are later finished to ensure that the design loads are transferred from the beam to the column. The development phase of these concepts is dealt with in this paper.

The capacity of samples, close to reality, of the composite girders of Möller has been explored experimentally and computationally. Here, the first objective was the experimental investigation. By examining the girder's behaviour, the numerical approach could be settled as the second objective.
Accordingly, a brief historic review is given, the experiments performed described, the numerical method applied presented and the corresponding results compared. The experimental and numerical results show good agreement.

This paper describes the design and construction of a high-rise steel building in Bucharest. The steel structure was designed according to the recently adopted Eurocodes and its performance was investigated using advanced techniques, including seismic performance-based methodology and wind tunnel tests. Robustness under extreme loading conditions was also investigated. The ECCS awarded the project a European Steel Design Award in 2007.

No short description available.

No short description available.

No short description available.

No short description available.

• Towers and Foundations for Wind Energy Converters in On- and Offshore Operation
• Steel Structures, Culture and Sustainability
• ICMS 2011 - XII International Conference on Metal Structures
• The 6th International Conference on Thin Walled Structures

No short description available.

No short description available.

Astronomy has experienced a great boost over the last 20 years. As a consequence, the telescopes used are getting larger and larger. In the past, radio telescopes with a reflector diameter of up to 100 m were built. Now, even optical telescopes are being planned with main mirror diameters exceeding 40 m! For all these telescopes the structural system - the steel structure - and the related mechanical components - the bearings and drives - are the “backbone” for the optical elements and play a major role in the planning, construction and related overall costs.
From the structural engineer's point of view, the design and construction of a telescope structure is very different from all other applications of steel structures. The design is not dominated - as it usually is - by issues of strength and stability, but mainly by issues of deformations and dynamics. The requirements for the structural system have to be developed in close cooperation with the overall telescope system engineer, who has to integrate the needs of the astronomers, the optics engineers, control engineers, etc. From the market point of view, there are only a few large telescope projects in progress worldwide, and not many structural engineers are working in this field; so no specialized companies are available for the manufacture and erection of large telescope structures.
This situation resulted in the emergence of a small group of project managers and engineers in Mainz, Germany, who were and are involved with many large telescope structures worldwide. This paper explains the specific design and construction issues by way of two current examples: the 64 m Sardinia Radio Telescope (SRT) under construction at San Basilio, Sardinia, and the 30 m Large Cherenkov Telescope (LCT) under construction at Gölschau near Windhoek, Namibia.

It has been a long time since seismic isolation was invented with the aim of protecting lives and structures against earthquakes. Seismic isolation is achieved by installing special bearings, so-called isolators, between the foundations of buildings or the piers of bridges and the superstructure. These isolators support the structure in the vertical direction and at the same time allow horizontal movements during earthquakes so that the seismic force applied to the superstructure can be much reduced. In Japan elastomeric bearings are often used for this purpose and existing seismic-isolated structures have demonstrated their effectiveness in the past. A number of research projects concerning elastomeric bearings have been carried out and their performance with respect to compression and shear loads is well understood. However, not much attention has been paid to their characteristics with respect to tensile loads. In some design standards a certain degree of tension in rubber bearings is already allowed to occur during earthquakes. This is inevitable since the ability of rubber to sustain tension was discovered and in seismic isolation applications in high-rise buildings and bridges there is a possibility that isolators undergo tension due to the overturning moment. There are, however, still many uncertainties; for instance, the influence of damage to or cavities within the rubber caused by tension, the interaction between the shapes and dimensions of bearings and the tensile strength, and the influence of the out-of-plane deformation of flanges are not well understood. Currently, the Japanese design rules for both bridges and buildings regulate the allowable tensile stress without distinguishing the type of rubber, shapes or dimensions. This merely empirical value will need to be reconsidered.

No short description available.