Strengthening of openings in elliptical heads and ANSYS analysis
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Dear experts, there is a tank with a design pressure of 2.5 Mpa and a cylinder diameter of 500 mm, in which a hole of 350 mm has been made. Based on experience, it seems that if an algorithm for equal-area reinforcement is used, reinforcement rings must be added (of course, large openings cannot be calculated using the equal-area method). However, simulation calculations using ANSYS showed that the analytical value of SII is less than 1.5 KSm ； With the requirement that SIV < 3KSm, it seems that no reinforcement measures are necessary. The analysis method is not used very often; I’m not sure whether this connection opening can be left without reinforcement based on the simulation results
If there are no issues with the force and displacement boundary conditions, then no reinforcement is required if the analysis shows that it isn’t necessary. Pay special attention to the effect of bending moments at the edges of the holes; in cases with large openings, these bending moments often have a greater impact than internal pressure.
So, how is it determined whether the displacement is acceptable? I don’t see any basis for judgment in the analysis criteria.
If the spatial dimensions permit, directly changing the radial section connection should be more reasonable than making openings in the head!
With a diameter of 500 mm and a hole of 350 mm in size, this is already beyond the scope of the equal area method. One of the analysis methods allows for calculation using SW6 (instead of ANSYS); it should be possible to carry out such calculations. When using software, it involves local stress analysis. Is a reinforcement ring needed for DN350? It would be better to thicken the cylinder