CEN TS 19102 ‐ Design values and material constants derived from tests

Abstract

Prestressed membrane structures are designed using limit state design in conjunction with the partial factor concept in accordance with EN 1990; actions are taken according to EN 1991 and combinations of actions according to EN 1990. CEN/TS 19102:2023 [1] provides a European framework for the verification of membrane structures. At the same time, the mechanical material properties required for the analysis – stiffness parameters for numerical analysis and compensation values for cutting pattering as well as strengths as the basis for resistances for member and detail verifications – still have largely to be defined on a project‐specific basis or determined by testing. This applies to coated fabrics (PVC/PES, PTFE/glass) as well as for foils (ETFE).

The paper classifies the mechanical tests referenced in CEN/TS 19102:2023 [1] and shows which parameters are typically derived from them. A focus is placed on determining stiffness parameters from biaxial tests (reference EN 17117‐1:2018 [2]) as well as strength parameters from short‐term uniaxial tensile tests (EN ISO 1421:2016 [3] or EN ISO 527‐3:2018 [4] with the normative Annexes of CEN/TS 19102:2023 [1]), including relevant detail specimens. Practical questions regarding the specification of biaxial test procedures (stress level, load history, cycles) and the evaluation of the measured data are discussed; by way of example, a least‐squares approach for identifying orthotropic stiffness parameters is presented. The aim is a transparent, reproducible basis for defining test requirements and deriving mechanical input values at the interfaces between all parties involved in the planning and execution process.