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<p> Up to now, no comprehensive design standard for tensile membrane structures exists either on national or European level. Currently, the development for a European design standard for tensile membrane structures made from technical textiles and foils is under way, based on the principles of EN 1990 “Basis of Design”. The work aims to establish a Eurocode “Tensile Membrane Structures”, that covers the design of pneumatically and mechanically prestressed technical textiles and foils. The paper gives background information on the requirements for a new Eurocode, the structure of the current draft standard, the state of the development with regard to the content, and it gives a “road map” to reach the objective: it explains the upcoming steps on European and national levels, points out fundaments still to be established and necessary research work still to be conducted in order to come to a comprehensive and widely accepted design standard.</p>

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One important and challenging aspect of the design process for tensile membrane structures is the determination of biaxial material stiffness parameters. Coated textiles that are used as architectural fabrics display highly nonlinear and anisotropic stress-strain behaviour under biaxial tensile stresses. Nevertheless, in state-of-the-art structural analyses, the behaviour of these coated textiles is often simplified to a linear-elastic plane stress relationship, where the elastic constants are "tensile stiffness" and "Poisson's ratio." The elastic constants must be determined for each material using biaxial tensile tests. Several different biaxial test procedures to determine the elastic constants exist worldwide, and these procedures yield various sets of elastic constants with a wide spectrum of stiffness parameters. At the same time, design engineers have no guidelines to assess which set of parameters is appropriate for a specific design situation. This paper compares two different methods of determining stiffness parameters using theoretical and experimental analyses. The variation in structural analysis results due to stiffness parameters that were determined using different techniques is demonstrated using three types of PES/PVC materials from two material producers. Furthermore, this paper provides guidance regarding the manner of evaluation of sets of elastic constants and the modification of the evaluation of experimental biaxial tests, if required. Information is also provided concerning the applicability of the investigated procedures.Tensile or membrane structures are often incorporated into modern infrastructure applications as a means to achieve elegant structural forms with low self-weight. Examples can be found in bridges, long-span roofs and temporary or special structures. Due to their low self-weight and limited redundancy, these structural forms can present numerous unique design or construction challenges. Their structural response must be fully understood under the temporary configurations occurring during construction. The unique mechanical properties of non-traditional materials frequently used in tensile or membrane structures can also present specific challenges or constraints.This issue of Structural Engineering International contains a special series of six scientific papers to highlight some of the recent developments in the field of Tensile and Membrane Structures.The first two papers in this series examine different aspects of the design and performance of structures constructed from light, fabric membranes. Uhleman et al. present a study that contrasts different standardized protocols used to arrive at design parameters for the modeling of material properties of textile fabrics. A paper by Milosevic examines the influence of concentrated loading on the deformation characteristics of a membrane structure.Beam string structures, which have seen increased adoption for use as long-span roof systems, are notable because their active change in geometry during construction needs to be co...

In the past five decades, reinforced coated textile membranes have been used increasingly as building materials, which are environmentally exposed. Thus, their weathering degradation over the service life must be taken into account in design, fabrication, and construction. Regarding such structural membranes, PVC (polyvinylchloride)-coated PET (polyethylene terephthalate) fabric is one of the most common commercially available types. This paper focuses on the backbone of it, i.e., the woven PET fabric. Herein, weathering of uncoated PET, as the load-bearing component of the composite PET-PVC, was studied. This study assessed the uniaxial tensile strength degradation mechanisms of uncoated PET fabric during artificial accelerated weathering tests. For this purpose, exploratory data analysis was carried out to analyze the chemical and physical changes which were traced by Fourier transform infrared spectroscopy and molecular weight measurements. Finally, with the help of degradation mechanisms determined from the aforementioned evaluations, a degradation pathway network model was constructed. With that, the relationship between applied stress, mechanistic variables, structural changes, and performance level responses (tensile strength degradation) was assessed.

Manifold variations of the mechanical behavior of structural woven fabrics appear in the first load cycles. Nevertheless, invariable states, i.e., mechanically saturated states, can be approached by multiple monotonous load cycle biaxial tests. In a state acceptably close to the ideal saturated state, the stress–strain paths reveal the elastic share of the initially inelastic stress–strain paths of woven fabrics. In this paper, the mechanical saturation behavior of two types of PTFE-coated woven glass fiber fabrics is examined and compared to the recently reported saturation behavior of a PVC-coated polyester fabric. With the help of the saturation test data, an extrapolation function is developed that facilitates an estimation of late cycle stiffness behavior based on measured early cycle behavior. Furthermore, the considerable impact of late cycle properties on structural analyses is shown exemplarily in the numerical simulation of a prestressed fabric structure by comparing results achieved from late and early load cycle stiffness parameters.