Optimization of Wire-Winding and Shrink-Fit Combination in Pressure Vessel Reinforcement

Abstract

In thick-walled pressure vessels design, combination of reinforcement techniques is preferred in comparison with their solo applications. Wire-winding and shrink fit are two common techniques which can be used in order to introduce beneficial compressive residual stress in the core of thick-walled pressure vessels. An optimized combination of these two techniques would lead to the integration of their advantages. The purpose of this paper is to optimize the design of a two-layered cylinder for maximum fatigue life expectancy under the combinations of wire-winding and shrink fit techniques. The layers thicknesses and radial interference of shrink fit are treated as design variables by considering different number of wire layers. The numerical optimization procedure known as the Simplex Search Method is employed to optimize the variables. Also, the fatigue life is calculated based on ASME code for high pressure vessel technology. The fatigue life was compared for different cases. The results show that by using proper combination, significant life enhancement can be achieved as high as 30 times in comparison with a wire-wound vessel. Also, it could reduce the required number of wire layers for a constant fatigue life by about 80%, which is very desirable due to difficulties of wire-winding process.