Abstract
Pressurized enclosures with obround cross sections are common components in the petrochemical industries. Since no theoretical solutions are currently available, the analysis and design of such components mainly relies on empirical or numerical analysis methods. In engineering practice, the determination of shell wall thickness requires complex iterations. In this study, obround shapes are regarded as curved and straight segments with corresponding boundary conditions, respectively. The geometry and boundary conditions of each segment are relatively simple. The theoretical analysis of each segment was performed separately. By combining the existing closed-form solutions, a theoretical solution that partially satisfies the coordination of deformation at segment junction is obtained. The proposed combined solution can accurately describe the stress and displacement distributions of an obround shell under internal pressure. Considering the uniqueness of the elastic solution, the proposed solution is the closed-form theoretical solution for pressurized obround shells. When the straight segments of the obround section disappear, the obround becomes a circle. The proposed solution returns to the solution of cylindrical shell or Lame’s solution. The proposed solution can be considered as extended Lame’s solution. The solution provides a new theoretical analysis method. It is simpler, more efficient, and more accurate than empirical methods and numerical analysis. It is expected to change the status quo that the analysis of obround components relies on empirical formulas and numerical analysis, and to develop a new design method for obround components.
