INVESTIGATIONS ON THE DESIGN OF MEMBRANE STRUCTURES WITH THE SEMI-PROBABILISTIC SAFETY CONCEPT

The semi-probabilistic safety concept was developed for limit state equations that are linear or mildly non-linear. EN 1990 (Eurocode 0) provides simplified design rules in case of non-linear functional relations between actions and their effects, which are based on a distinction between under- and over-linear behaviour. We discuss circumstances in which this classification can be ambiguous in particular due to pre-stressing of membranes. We then show the effect of the classification on the reliability: the simplified classification of EN 1990 can lead to inconsistent reliability levels for structures with non-linear behaviour. Finally, we discuss the the consequences of our investigations on the semi-probabilistic safety concept for non-linear structures such as membranes.