Questions about perforation reinforcement calculations
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The shell section used in the calculation for opening reinforcement is one that is parallel to the longitudinal welds; why isn’t a section parallel to the circumferential welds chosen instead?
This post was last edited by zhangjuhua on 2017-8-12 at 20:09. Generally, the stress in the longitudinal section of the cylinder is twice that in the transverse section; accordingly, the required thickness for calculation is also twice that of the transverse section. This represents a critical section. If the longitudinal section is reinforced adequately, the transverse section will automatically meet the requirements. However, when the axial load is high or the size of the transverse openings is much larger than that of the longitudinal openings, it is not guaranteed that the transverse section will meet the reinforcement requirements, in which case both the longitudinal and transverse sections need to be checked
The circumferential stress is twice that of the axial stress; this is due to the cross-section with longitudinal welds parallel to each other, as explained on the second floor
It should be calculated for both, but in the case of longitudinal stress, it involves the two components of axial force; generally, once the longitudinal stress is taken into account, there are basically no issues with the axial stress, provided that circular holes are used. . If it’s an oblong or oval hole, it’s different. . Basically, it all needs to be calculated. .
The principle explained on the second floor is correct, but regarding the image in 150, I think it is just a schematic diagram and doesn’t carry any deeper meaning. There’s no need to overinterpret it.
When the opening strength is not high, the calculation is generally based on the overall welding coefficient of the equipment; this ensures that the welding coefficient for the entire device is consistent, and regular designs follow these rules