Design of Hipped Hypar Shells

The behavior of hipped hypar shells is significantly different from that assumed in the membrane. The concept of equal arch and catenary actions is no longer valid. A finite element analysis of a typical shell indicates that the loads are carried by dominant arch actions, spanning across diagonally opposite supports. The investigation of forces and bending moments in the membrane and edge members lead to a method for the preliminary design of such shells. The method includes procedures for local membrane thickening necessitated by stress concentration or by bending effects.