Large Rect. Opening in a Cylindrical Shell

[flexy]

I am working on a large expansion joint design. This expansion joint has a very large rectangular nozzle (88" x 53") that goes radially into a round shell (78" OD). The long side of the rectangular opening runs parallel to centerline of the 78" shell.

I know that I can use Appendix 1-7 for the analysis of the stress and reinforcement. But, can I convert the rectangular shell into a round shell of equal area, or is there a method avaailable that addresses this. I have heard that Dr. A.E. Blach had some analysis for this situation. Has anyone seen this?

Any help would be greatly appreciated!

 

[innovation2]

That is a new one that I haven't heard before. I doubt that you could consider the rectangle as a circle because the modes of failure would be different with pressure. With the rectangle you must consider bending moments in the corner which is completely different than the membrane stress a cylinder experiences under pressure. You may find some insight in App 13. Look there and you will find the areas of interest regard a rectangular opening.

I have a good feeling that this will fall into U-2(g), good engineering practice.

 

[flexy]

Thanks inno2. I know there are shell and tube condenser manufacturers that face this issue all the time. just not sure how they approach it. i suspect that they use a standard approach that has not resulted in failure. what that approach is, is anyone's guess. i may have to FEA the thing to determine a course of action.