                                !!" # $  %   &’()   *+, -./ Importance of material properties in fabric structure design & analysis Benjamin N. BRIDGENS *, Peter D. GOSLING a , Caroline H. PATTERSON a , Stuart J. RAWSON a , Newton HOVE a * a Newcastle University, School of Civil Engineering and Geosciences Drummond Building, Newcastle upon Tyne, NE1 7RU ben.bridgens@ncl.ac.uk Abstract Coated woven fabrics are used in state-of-the-art structures yet broad assumptions are made in both material testing and analysis. Design is not codified and relies heavily on experience and precedent. Increasingly architects are moving away from conventional fabric forms, often utilising lower levels of curvature and new materials. The result is less efficient, highly stressed structures which may be more sensitive to (poorly quantified) fabric material properties. This paper considers the importance of material properties and structural geometry in the design and analysis of tensile fabric structures. Three typical tensile forms (conic, hypar & barrel vault) have been considered. Recommendations are given on the types of structure that are sensitive to variability in material properties, and ‘rules of thumb’ are proposed for the efficient design of fabric structures. Keywords: fabric structure, tensile structure, efficient design, hypar, conic, barrel vault. 1. Introduction 1.1. Architectural fabric material behaviour Coated woven fabrics are used in state-of-the-art structures yet broad assumptions are made in both material testing and analysis. A combination of non-linear stress-strain response of the component materials (yarn and coating), combined with the interaction of orthogonal yarns, results in complex (non-linear, hysteretic, anisotropic) material behaviour (Bridgens, Gosling et al. 2004 [2]). Full quantification of the response of coated woven fabrics to in- plane loading (biaxial and shear) is time consuming and costly, and arguably has not yet been achieved. Even if comprehensive test data were available, techniques to utilize this data in structural analysis are in their infancy. 1.2. Tensile structural forms Architectural fabrics have negligible bending or compression stiffness. The shape of the fabric canopy is therefore fundamental to its ability to resist all applied loads in tension. To