Theory of Cylindrical Composite Pressure Vessels with Shape Memory Ring Stiffeners

The paper presents an approach to design of cylindrical pressure vessels subjected to an internal pressure. The burst pressure of such shells is often increased by the use of ring stiffeners. However, these stiffeners should have a significant moment of inertia to be effective. This may limit their usefulness in the situations where there are space or weight limitations. The problem can be solved by using slender shape memory alloy (SMA) rings. The support provided by these rings is due to recovery stresses generated as a result of a reverse martensitic transformation. The paper presents an exact analytical solution of the problem of the interaction between SMA rings and a multilayered symmetrically laminated cylindrical shell. The approach employed in the paper utilizes a generalization of the classical Timoshenko's solution for isotropic cylindrical shells with ring stiffeners and an empirical or analytical constitutive law for the shape memory material. Numerical results indicate that SMA rings can be an effective tool in design of pressure vessels.