Increasing the Safety of Tensile Structures

2. Rainer Blum, Ludwig-Finckh-Weg 17, D 71229 Leonberg, Germany

Abstract: An actual issue arising from daily work in the quality assessment of large structures is the safety of structures. Considering the most common failures of membrane roofs we can detect two main causes: either detail failures or failures of the material. To avoid failures of details in Germany, e.g., a quality assurance system for every project is being executed. Testing all structural important details of a structure before and during fabrication confirming the necessary safety factors minimizes risks very effectively. However this does not avoid all problems occurring on site as many failures are caused by harming the material itself. In this paper failures will be shown on which the origin of the problems will be demonstrated: mechanical damages, folding etc. caused during manufacturing, transport and use. The following questions will be discussed: Where do tears come from, how could they be avoided on one hand and on the other hand, in case they have happened: how can we predict the influence on the safety of the structure? Safety reducing aspects and test methods to elaborate the residual strength of materials will be presented.