Full Description

Due to the urgency of gaining information on stresses near openings in pressure vessels, a rather comprehensive experimental program has been conducted over the past nine years. It was anticipated that the results of the research would be valuable for the following three purposes:

(1) To evaluate the effect of geometric parameters and methods of local reinforcement,
(2) To provide specific information that may be of immediate use to designers and stress analysts for types of pressure vessels most commonly used, and
(3) To provide experimental data which will be useful in developing or checking the validity of theoretical solutions for stresses.

The over-all program was coordinated by the Reinforced Openings Subcommittee of the Pressure Vessel Research Committee and included similar photoelastic tests conducted by M. M. Leven at the Westinghouse Research Laboratories. In some cases part of the models in an integral series were tested by Leven and part of them were tested by the authors. Consequently, models in both series are included in a combined index given at the beginning of this Bulletin. Leven's results are reported separately in reference (1), also located in this Bulletin.

As data became available for each model, complete summary sheets were prepared and were widely distributed to interested persons. A complete set of summary sheets is included in the Appendix. Results of the first few models were given in WRC Bulletin 51. A comprehensive interpretive report based upon information available in 1962 was written by J. L. Mershon who has also prepared a sequel report which includes analyses of all models in the program. In view of the above listed factors, the scope of this present report will be limited to a description of the experimental techniques, presentation of the results, and a discussion of the probable accuracy.

It should be mentioned that the complete description of stresses near an outlet in a pressure vessel is an extremely complex matter. This is especially true of cylindrical vessels. Even for spherical vessels, which possess axial symmetry, the problem is not simple because more than one area of stress concentration usually occurs. Hence the mere listing of the maximum stress or the stress concentration factor for each model would not be sufficient. Curves giving complete stress distributions on outer and inner surfaces are given for each model. Data from these should have a higher probability of satisfying the needs of designers and mathematicians.

For some of the models, the stress distribution across the thickness from inside to outside surfaces was computed at key locations. From these results the stress resultant and stress couple may be obtained and compared with solutions derived by shell theory.

Product Details

Published: 1966 Number of Pages: 80 File Size: 1 file , 4.1 MB