"[T]wo primary research questions can be formulated: [1] What is for a shell of hemispherical geometry, with given material properties, given support conditions, and subjected to a given load, the knock-down factor which indicates the difference between the linear critical buckling load and the actual critical buckling load taking into account imperfections and geometrical and physical nonlinearities? ...[2] Can high strength fibre reinforced concrete add to the trend towards greater spans and thinner shells with possibilities for even more slender structures? To obtain an answer to the research questions a series of analyses (linear elastic, stability, geometrically nonlinear and geometrically and phy sically nonlinear) is performed on a given hemispherical shell: the Zeiss planetarium shell."