P 163 - Investigation of wind-induced vibrations in steel chimneys

P 137 - Evaluation of fracture mechanical failure concepts with regard to a reliable prediction of component behaviour According to the current state of the rules and regulations for steel construction (Eurocode 3, /1/), the use of high-strength steels with yield strengths above 450 N/mm is severely restricted or excluded. This is due to the conventional assessment criteria and safety philosophies. However, several concepts have been developed in recent decades to assess the failure behaviour of components, which are based on fracture mechanics approaches and thus enable the component behaviour to be quantified. These methods have not yet found their way into design regulations for steel construction and are to be tested for their applicability as part of this research project. This research project also aims to show whether a fracture mechanics assessment of material and component behaviour can provide advantages for the application of high-strength steels. The results should encourage a reconsideration of the currently valid regulations and, if necessary, the use of fracture mechanics methods as a basis for assessing the failure behaviour of materials and components, so that high-strength steels can be included in the regulations. We would like to briefly explain the following about the research work carried out: The base material and welded joints of two steels of different toughnesses of the grades StE 355, StE 460, StE 690 as well as a St 37-3 and X8 Ni9 were analysed. Initial investigations into the suitability of these materials were carried out using tensile and notched bar impact tests. To check the existing fracture mechanical failure concepts, tests were carried out with large tensile specimens similar to components at - 20 " C (- 160 ° C for X8 Ni9). These specimens were provided with centre flaws with flaw lengths that are just permissible according to Eurocode 3 (draft 1983) for tensile structures and also with a significantly greater flaw length. The fracture mechanics tests were confirmed by the large tensile tests with regard to the toughness properties in the base material and in the HAZ. An evaluation of the results of the large-scale tensile tests using fracture mechanics concepts led to reliable estimates of the failure behaviour of the large-scale specimens, with the smallest deviations occurring between prediction and experiment when finite element calculations were used to determine the fracture mechanical stress. The simplified ultimate load model of Eurocode 3 can be applied to tensile bars made of high-strength steels on the basis of the test results and opens up the possibility of designing and building economically with high-strength steels. STUDIENGESELLSCHAFT FÜR ANWENDUNGSTECHNIK VON EISEN UND STAHL e.V. Publication: 1990 Authors: Prof. Dr rer. nat. W. Dahl, Dipl.-Ing. R. Hubo, Dr.-Ing. B. Müsgen, Dr rer. nat. H.-J. Kaiser, Prof. Dr.-Ing. G. Sedlacek, Dr.-Ing. Image

P 104 - Investigations on the reduction of noise emission from steel railway bridges by design measures As part of the research project "Investigation into the reduction of noise emission from steel railway bridges through structural measures", extensive theoretical and experimental investigations were carried out on a railway box girder bridge on behalf of the German Federal Railway and the German Steel Construction Association under the auspices of the Studiengesellschaft für Anwendungstechnik von Eisen und Stahl e.V. (Study Society for Application Technology of Iron and Steel). The main part of the investigations was carried out at the Krupp Research Institute in Essen and the Thyssen Research Centre in Kassel in cooperation with the DB Testing Institute in Munich. Sound intensity measurements and an operational vibration analysis were carried out by the company Deutsche Metravib GmbH, Ostfildern. The Federal Railway Central Office in Munich was responsible for providing the measurement trains, preparing the measurement route and coordinating all operational procedures. The Krupp Research Institute in Essen was responsible for the technical management of the project. The project began on 1 July 1984, but preparations had already been made in the spring of 1984. After preliminary investigations on approx. 10 railway bridges, the box girder bridge over the Aitrach (line kilometre 16.287, the single-track line between Leutkirch and Memmingen) built in 1980 was chosen as the test object. Although this bridge can be described as particularly quiet in comparison to other steel bridges originally considered and also to the open line, it was particularly suitable for the fundamental investigations planned here, above all because of its simple and clear construction. This report summarises all the important results and findings resulting from the project. Where cross-references ("HB") are made at certain points to another source, this is in all cases a planned documentation that may be set up at a central location at a time not yet determined. Publication: 1988 Authors: o.A.

P 100 - Development of characteristic values for the production of cold rolled profiles from the point of view of economical production of dimensionally accurate profiles Cold profiling using the roll forming process is a forming process that has been used industrially for over half a century. It allows the production of cold-formed profiles with consistent and high dimensional accuracy, some with sharp-edged bends, many curved sections, complicated double folds, with - if desired - targeted work hardening of the starting material and finally the combination of profile shaping with further processing steps such as punching, beading and bending. Although the diverse requirements and the general technical development of mechanical engineering have led to a wide variety of roll forming systems over the course of time, the technology of roll forming is still largely based on practical experience. This applies both to the dimensioning of production facilities and to the design of forming tools. This unsatisfactory situation can probably be explained essentially by the fact that the entire process - in addition to the rather difficult geometric relationships of forming - is governed by numerous working conditions which influence each other. For this reason, the Technical Committee of the German Cold Forming Association has been working closely with a well-known plant manufacturer for several years on the development and dimensioning of a machine and drive concept for research purposes. A machine and control technology solution was developed and realised which for the first time makes it possible to empirically investigate the interactions between the parameters of the production process and the properties of the product in a reproducible manner. This research work was carried out on behalf of the Studiengesellschaft für Anwendungstechnik von Eisen und Stahl e.V. by Prof. Dr.-Ing. D. Schmoeckel, Institute for Forming Technology at Darmstadt Technical University. In addition to confirming some of the results of earlier investigations, new findings of practical relevance were obtained. This applies in particular to the experiments on slip reduction, which resulted in a drastic saving in the energy used, and on the relationship between the quality of the finished product and the selected forming strategy. These results represent a step towards a better understanding of the complex manufacturing process, but at the same time demonstrate the need for further intensive efforts to conduct in-depth research into roll forming technology. The research project was funded by the Federal Ministry of Research and Technology (BMFT) and was supervised by Kernforschungsanlage Jülich GmbH (KFA) as the project sponsor for the raw materials research programme. STUDIENGESELLSCHAFT FÜR ANWENDUNGSTECHNIK VON EISEN UND STAHL e.V. Publication: 1986 Authors: Prof. Dr.-Ing. D. Schmoeckel, Dipl.-Wirtsch.-Ing. U. Eichler