P 110 - Measures to improve utilisation and increase the load-bearing capacity of cold profiles

P 111 - Cold-formed, lightweight steel profiles as structural components in structural engineering applications The expansive development in the field of thin-walled cold-formed components used as linear and planar structural components (cold-formed profiles and profiled sheets) poses a variety of problems for partners in the construction process, as this construction method involves a development towards the structural unity of the load-bearing structure and interior design. The basic concept of lightweight construction technology is the end product - the wall, the room or the building - thanks to the possibility of forming flat construction elements, to which the user makes justified demands in terms of safety, functionality, environment and economy. Lightweight construction technology therefore lies at the intersection of different schools of thought and disciplines, which requires the dismantling of facultative boundaries and the integration of knowledge across many disciplines. These overarching problems form the framework of the research project "Cold-formed lightweight steel profiles as structural components in structural engineering applications"; they are systematically presented in section 2 of the report. The choice of the actual research object is also to be understood in this sense. The so-called "V-beam" is a load-bearing structure composed of cold-formed profiles and trapezoidal profile panels and designed as a hall construction system that can fulfil a wide range of functional requirements. The system thus exemplifies the possibilities of lightweight construction technology with regard to interior design, the adaptation of the supporting structure to installation requirements for various media and acoustic requirements, while the supporting structure itself is an example of the functional and statically possible design of the individual load-bearing elements with regard to the forms of loading and the rational "online" production of the construction elements, transport and assembly, which is reported on in Section 3. The overall concept was studied in detail at the beginning of the research project on a model (1:30) by the project team. This model construction is worth mentioning because the "hands-on" involvement with the very slender and flexible supporting structure components, followed by the assembly and the associated increase in the load-bearing capacity and rigidity of the supporting structure via the flat discs to the spatial system, simultaneously awakened a feeling for possible load-bearing conditions and motivated the task. The theoretical and experimental investigations on parts of the overall structure were focussed on the load-bearing behaviour of the structural components and their interaction in accordance with the objective of the research project. The experimental investigations, which were planned and carried out by H. Urschel and R. Wolfram, included the study of the girder webs consisting of trapezoidal profiles under predominantly shear loading and consideration of the load transfer at the support, tests on elastically bedded cold-formed chord profiles and the study of the connecting means between chord and web and in the vertical joints of the trapezoidal profiles. The test results are presented in connection with the analytical treatment of the three sub-problems mentioned. Section 4 contains the analysis of the shear field behaviour, for which R. Wolfram is responsible, section 5 the analysis of the load-bearing behaviour of the chords carried out by H. Urschel and section 6 the evaluations of the load-bearing behaviour of the connections in entire structures jointly prepared by both employees. Section 7 rounds off the research report with recommendations for a future set of rules for the dimensioning and structural design of load-bearing structures made of thin-walled cold-formed components and trapezoidal profiled sheets. Publication: 1985 Authors: Prof. tekn. dr. R. Baehre

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