On the Design Process of Tensile Structures Rosemarie Wagnerl Fachhochschule Miinchen Fachbereich Architektur Karlstrasse 6,D-80333 Miinchen,Germany R.Wagner@fhm.edu Web page:http://www.lrz-muenchen.de/~architektur Summary.The influence of the development of computer programmes and auto- matic generation of cable nets and membrane structures will be shown in some er- amples.The main interest is laying on new evaluation methods of cable nets and membrane structure and the design process of membrane structures,integrating the material behaviour of coated fabric. Key words:Design process,cable nets,membrane structures,inflated structures 1 Introduction The design process of pretensioned structures such as cable nets and membrane structures is influenced by the development of computational methods.While the first methods of form finding had been physical modelling with fabric,wire nets or soap films,today several numerical methods of form finding are developed based on the force density method [1,2],the principle of minimal surfaces [3,4]using dynamic relaxation [5,6]or other approaches in fulfilling the three-dimensional equilibrium Further process has been carried out in the form finding with an anisotropic stress distribution [7].All methods have in common that no material laws are necessary finding an equilibrium of the three dimensional shape for given stress distributions, boundary conditions and supports.These shapes of equilibrium should ensure in the built structure a homogeneous distribution of the tension stresses.In reality the material behaviour,process of cutting patterns,manufacturing and pretensioning on site influencing the stress distribution,wrinkles and regions of over stress are obvious.can be seen and measured. The design process of pretensioned structures needed to be extended taking into account evaluation methods for shapes of equilibrium in relation the mate- rial behaviour and process of prestensioning.More realistic modelling of membrane structures is necessary including the strips in width,orientation of the fabric and seams for analysing the load charring behaviour.The process of reassembling flat- ten strips had already been proposed for a rotational symmetric hat type tent [8]. The process of form finding can be embedded in a design process including cutting pattern und structural behaviour under external loads.The load bearing behaviour 1 E.Onate and B.Kroplin (eds.).Textile Composites and Inflatable Structures,1-16. 2005 Springer.Printed in the Netherlands.On the Design Process of Tensile Structures Rosemarie Wagner1 Fachhochschule M¨unchen ¨ Fachbereich Architektur Karlstrasse 6, D-80333 Munchen, Germany ¨ R.Wagner@fhm.edu Web page: http://www.lrz-muenchen.de/∼architektur Summary. The influence of the development of computer programmes and auto￾matic generation of cable nets and membrane structures will be shown in some ex￾amples. The main interest is laying on new evaluation methods of cable nets and membrane structure and the design process of membrane structures, integrating the material behaviour of coated fabric. Key words: Design process, cable nets, membrane structures, inflated structures 1 Introduction The design process of pretensioned structures such as cable nets and membrane structures is influenced by the development of computational methods. While the first methods of form finding had been physical modelling with fabric, wire nets or soap films, today several numerical methods of form finding are developed based on the force density method [1,2], the principle of minimal surfaces [3,4] using dynamic relaxation [5,6] or other approaches in fulfilling the three-dimensional equilibrium. Further process has been carried out in the form finding with an anisotropic stress distribution [7]. All methods have in common that no material laws are necessary finding an equilibrium of the three dimensional shape for given stress distributions, boundary conditions and supports. These shapes of equilibrium should ensure in the built structure a homogeneous distribution of the tension stresses. In reality the material behaviour, process of cutting patterns, manufacturing and pretensioning on site influencing the stress distribution, wrinkles and regions of over stress are obvious, can be seen and measured. The design process of pretensioned structures needed to be extended taking into account evaluation methods for shapes of equilibrium in relation the mate￾rial behaviour and process of prestensioning. More realistic modelling of membrane structures is necessary including the strips in width, orientation of the fabric and seams for analysing the load charring behaviour. The process of reassembling flat￾ten strips had already been proposed for a rotational symmetric hat type tent [8]. The process of form finding can be embedded in a design process including cutting pattern und structural behaviour under external loads. The load bearing behaviour 1 E. Oñate and B. Kröplin (eds.), Textile Composites and Inflatable Structures, 1–16. © 2005 Springer. Printed in the Netherlands