The Effect of the Layup on the Stability of Composite Cylindrical Shells

Abstract

Fiber reinforced plastic laminated composites have conquered greater and greater territory in the field of engineering in the past decades for their high strength to weight ratio. By varying the layup structure their behavior can easily be modified. One of the applications, that is investigated in this article is the slit tube or cylindrical shell, that used as a structural element undergoes bending. These shells indifferent from their material may experience the snap-through phenomenon (this depends both on the material and geometry) in which the shell flattens and loses its stability to bending. Depending on the layup bistable behavior also can be achieved, i.e., the shell would have two different shapes that are in equilibrium without any constraint. In this article the effect of the layup is investigated both on the bistable behavior and the snap-through phenomenon. Geometric limitations for the bistability are calculated based on a simple beam model from the literature. The same model is used to find the snap-through moment for these shells as a function of the orientation angle. It is also proven that the flattening of the shell cannot be evaded by changing the layup structure. The results are confirmed by FE simulations where applicable.