10 Rosemarie Wagner Shape of equilibrium Cutting pattern Pretension of the plane strips Stress distribution Stress distribution Fig.12.Influence of the cutting pattern to the stress distribution of a membrane [21] Low High point point seams Cross section low points △zmm=20%of the span High point Low point Isometric view,scaling factor 1 100 Cross section high points Fig.13.Difference in z-direction between the reassemble shape and the shape of equilibrium 21] 3.4 Load Bearing Behaviour The load bearing behaviour is in general depended on: The flexibility of the structures including masts,bending elements such as arches, stay cables,anchorages and foundations The height of the pretension related to external loads The orientation of the cables or yarns related to the main curvature of the surface The curvature of the surface and The stress-strain-behaviour of the material The stability of the cable net or membrane structures is depending on the pre- tension.In structures with negative Gaussian curvature the pretension is only to reduce the deformation.The slag of the spanning direction causes a change in the system but no instability.10 Rosemarie Wagner Fig. 12. Influence of the cutting pattern to the stress distribution of a membrane [21] Fig. 13. Difference in z–direction between the reassemble shape and the shape of equilibrium [21] 3.4 Load Bearing Behaviour The load bearing behaviour is in general depended on: - The flexibility of the structures including masts, bending elements such as arches, stay cables, anchorages and foundations - The height of the pretension related to external loads - The orientation of the cables or yarns related to the main curvature of the surface - The curvature of the surface and - The stress – strain – behaviour of the material The stability of the cable net or membrane structures is depending on the pre￾tension. In structures with negative Gaussian curvature the pretension is only to reduce the deformation. The slag of the spanning direction causes a change in the system but no instability. Shape of equilibrium Cutting pattern Pretension of the plane strips Stress distribution Stress distribution Cross section low points Isometric view, scaling factor 1 : 100 Cross section high points High point Low point High poin Low point t seams 'zmax = 20 % of the span