Az erojáték és az anyagtulajdonságok hatása a téralakításra. A formakeresési módszerek fejlodésérol

Finding the desired form - whether architectural or structural - is one of the most important and most complex problems that a designer has to face. The most widely used approaches in form finding are drawings and physical or virtual models. It is quite common, that the (geometry) of the structural system must follow the previously determined architectural form. Our aim is to show some methods, which take into consideration the structural and material aspects from the very beginning of the design process, and hence significantly influence the architectural form. Form finding is an iterative process; therefore it is essential that the designer receives immediate feedback of the consequences of the alteration of the diverse parameters (e.g.: geometry, applied load). This is only feasible, if the behaviour of the structure is relatively easy to describe. This applies to both graphical and physical models. Structures in pure compression or tension are especially suitable for these applications, since a continuous stress field (under self-weight) can be well represented by a discrete force network. The hanging models of Antoni Gaudi and Frei Otto are based on this very principle. Karl Culmann, the inventor of graphic statics was also driven by the desire to find a method, which was interactive and helped to visualize the structural behaviour. The biggest challenge for both graphical methods and physical models is to overcome the inaccuracies occurring during the process. This could lead to considerable differences, in the structural behaviour of the model and that of the real structure, which could affect the latter"s stability. Following the scaling of the original model or drawing, the so-called square-cube law must also be taken into consideration. The wider application of numerical methods helped to overcome these problems, but visualization was lost. In case of masonry arches however, the material has very large resistance compared to the occurring stresses, which means, that the above described problems with graphical methods or physical models have much less significance for these structures. Similar observations can be made for some shell types. Due to the rapid development in the field of digital modelling, the graphical methods are being rediscovered: the computer easily overcomes the problem of inaccuracies, for instance. The current research in this field shows some promising results in the adaptation of these tools for the analysis of historical masonry structures and for the form-finding of free-form (masonry) shells.