Dessau-Rosslau, Germany 2006 - 2007

Design, planning and structural calculation:       
Prof.  Dr.  Robert Off
Prof.  Dr.  Robert Off, Sabrina Motaleb-Off, Nadine Defee
Students of the course Membrane Structures and members of the IMS e. V.
Prof. Dr. Robert Off, Nadine Defee

Bat-Wing-Sail Research Project

A frequent problem of small and medium sized membrane constructions is to effectively cover an area with a 4-point hyperbolic membrane construction. With free inclined edge cables the clouding and rain protection is poor compared to the overall size of the structure. Comparatively little area is covered.

One solution to the problems is a flexural resistant clamping of the membrane to a stiff member. This solves the area-covering problem but at the cost of aesthetics. The construction loses its charm, lightness and elegance.

The new approach of the bat-wing-sail may solve these problems. With this building method glass-fiber rods are inserted in the seams of the membrane. They cantilever over the edge cables of the membrane and enlarge the covered area up to 60 %. The typical shape of a leave or “bat” wing is the outcome. As a second advantage a reduction on the amount of pre-stress of the whole structure due to the inserted rods is expected. This may become very interesting for medium sized and larger membrane constructions in economic aspects.

Up to now the behavior of the bat-wing-sail was unexplored.

In spring 2006 the IMS started research on this new approach in cooperation with the Anhalt University of Applied Sciences. A bat-wing-sail was built at the workshop of the University for Research.