Nonlinear behavior of northlight reinforced concrete shells

The behavior of northlight shells is very sensitive to the boundary conditions at the top and bottom edges of the shell. The aim of this paper is to investigate the structural action of these shells at elastic, inelastic, cracking and ultimate load ranges with realistic boundary conditions at the top and bottom edges. The influence of construction method on the design and also the effect of concrete cracking, tension stiffening, nonlinear stress strain relations in compression, yielding of steel reinforcement and large deformations on the behavior of the shell are discussed. The full range behavior of a special 'S' type profile to suit the single shell situation and its superiority over the conventional profile are discussed. A brief description of the analytical model adopted in the Nonlinear finite element software used in this investigation is also presented.