Machine Dynamics Problems 2006, Vol. 30, No 2, 7−17 On Finite Element Modelling of Architectural Fabrics for Hanging Roofs Andrzej Ambroziak *) , Paweł Kłosowski *) , Krzysztof WoĨnica **) *) Gdansk University of Technology, **) Ecole Nationale Superieure d’Ingenieurs − Bourges ambrozan@pg.gda.pl, klosow@pg.gda.pl, krzysztof.woznica@ensi-bourges.fr Abstract This paper deals with the constitutive modelling and identification of coated woven fabrics properties. The authors give brief characterization of the constitutive models used for the material modelling and discuss in details the fundamental equations of the dense net model. The special identification method of the non-linear elastic properties of the coated fabric is presented. The material parameters are determined on the base of uniaxial tensile tests in the warp and weft directions. For the identification process, techniques using the least squares method are applied. Additionally, the results of the uniaxial tension tests are compared with biaxial tension tests. 1. Introduction The constitutive models have fundamental influence on the increase of the analysis precision and economical designing based on advantages resulting from the used materials. The coated fabrics are eagerly used in civil engineering structures, e.g. for membrane structures (see Fig. 1) and also for pneumatic constructions (see e.g. Pelczarski, 2004; Gerlic, 2004; Ambroziak et al., 2005)). For example, the roof of the Forest Opera in Sopot (see Fig. 2) is one of the first Polish structures of this type. Usually for threads net the following materials are used: polyamide, polyester, fibreglass and aramid fibres. Consequently it is possible to specify the following types of coating: PVC on polyester cloth, PVC on aramide weave, PTFE on fibreglass weave, silicone on fibreglass weave (see e.g. Houtman, Orpara, 2000; ĩuchowska, 2000). In advanced types of the coated fabric, the coating layer is sub-layered and one can distinguish adhesion layer, main coat, and the primer and topcoat layers. In the present paper a detailed investigations are performed for the Panama fabric and the Shelter-Rite architectural fabric type 9032. These fabrics are manufactured of polyester fibres and are both sides coated with polyvinyl chloride.