The project will develop new surface coupling schemes for computational staggered multi-field simulation and optimization of structures which are characterized by highest demands for the quality of the geometrical surface resolution. As a typical field of application the project will concentrate on fluid-structure-interaction (FSI) simulation of flexible, free-form shell and membrane structures, e.g. rotating wind turbine blades, flexible tent-like structures such as wide span stadium roofs subjected to wind or technical and natural tissues subjected to fluids etc. The physical modelling and the significance of the simulation results for such problems are dominated by the quality of the surface resolution, e.g. to precisely determine separation points of streamlines on the structure. High quality modelling of surface geometries and on this basis modelling of physical exchange mechanisms is decisive. The framework of isogeometric analysis (IGA) already proved in principle the qualitative superiority of merging CAGD and FEM-techniques by completely avoiding geometric discretization errors, typically for simple field problems.