Elastic-Plastic Computations as a Basis for Design Charts for Torispherical Pressure Vessel Ends

Abstract

A series of elastic-plastic calculations has been carried out on torispherical drumheads subject to internal pressure. From the results of this analysis, master curves have been prepared which are independent of factors such as the ratio of design stress to yield stress and the ratio of design pressure to test pressure. These curves provide a rational starting point, from which Code Drafting Committees can derive, in simplified form where necessary, design factors to meet the requirements of specific Codes of Practice. An example of this use of the master curves is included. Correlation between the theoretical analysis and the available experimental data on torispherical drumheads is shown to be good. Conversely, the experimental results show that drumheads designed using factors derived from the master curves will perform satisfactorily in service. The principles illustrated in this paper can be applied to many other types of component commonly used in the pressure vessel industry. In this way, it is possible to provide a series of master curves which would form a rational basis, common to all codes, for the preparation of detailed design rules.