Calculation of large openings in the cylinder of SW6
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This post was last edited by Feng Chuixiaodingding on 2017-10-9 at 12:33. Today, for a diameter of 900, a pressure of 0.35, a cylinder wall thickness of 12, and material Q345R, the calculated size for the connection pipe is DN600 with Q345R as well. With all other parameters remaining unchanged, a wall thickness of 12 is acceptable; 14 is also acceptable, while 16 is unacceptable due to a 4% decrease in performance, and 18 is unacceptable due to a 9% decrease. Although from an analytical perspective it’s not true that the thicker the wall, the better, well… . It does not exceed 2 times the wall thickness of the cylinder; the calculation for this fitting exceeded my expectations. **********Results of hole reinforcement calculation********** Port N1: Hole in a circular cylinder. Calculation method: Analysis based on GB150-2011. Calculated pressure: 0.35 MPa. Shell material: Q345R, nominal thickness 12 mm. Fitting material: Q345R, specifications φ610×12. S(Ⅱ) = 91.478; allowable value = 402.6 – acceptable. S(Ⅳ) = 129.08; allowable value = 475.8 – acceptable. Please note constraints such as hole spacing, material yield ratio, welding groove type, and inspection requirements. Acceptable (+11%). **********Results of hole reinforcement calculation********** Port N1: Hole in a circular cylinder. Calculation method: Analysis based on GB150-2011. Calculated pressure: 0.35 MPa. Shell material: Q345R, nominal thickness 12 mm. Fitting material: Q345R, specifications φ610×14. S(Ⅱ) = 81.957; allowable value = 402.6 – acceptable. S(Ⅳ) = 117.52; allowable value = 475.8 – acceptable. Please note constraints such as hole spacing, material yield ratio, welding groove type, and inspection requirements. Acceptable (+3%). **********Results of hole reinforcement calculation********** Port N1: Hole in a circular cylinder. Calculation method: Analysis based on GB150-2011. Calculated pressure: 0.35 MPa. Shell material: Q345R, nominal thickness 12 mm. Fitting material: Q345R, specifications φ610×16. S(Ⅱ) = 74.452; allowable value = 402.6 – acceptable. S(Ⅳ) = 105.74; allowable value = 475.8 – acceptable. Please note constraints such as hole spacing, material yield ratio, welding groove type, and inspection requirements. The actual external length of the fitting is 95 mm, which is too short; it must be increased to at least 98.793 mm. Unacceptable (-4%). **********Results of hole reinforcement calculation********** Port N1: Hole in a circular cylinder. Calculation method: Analysis based on GB150-2011. Calculated pressure: 0.35 MPa. Shell material: Q345R, nominal thickness 12 mm. Fitting material: Q345R, specifications φ610×18. S(Ⅱ) = 68.4; allowable value = 374 – acceptable. S(Ⅳ) = 93.322; allowable value = 442 – acceptable. Please note constraints such as hole spacing, material yield ratio, welding groove type, and inspection requirements. The actual external length of the fitting is 95 mm, which is too short; it must be increased to at least 104.79 mm. Unacceptable (-9%). ------------------------------------------------------------------------------------------- Updated on 20171009: The length of the fitting was changed to 110 mm; fittings with a thickness of 12 mm are more acceptable. **********Results of hole reinforcement calculation********** Port N1: Hole in a circular cylinder. Calculation method: Analysis based on GB150-2011. Calculated pressure: 0.35 MPa. Shell material: Q345R, nominal thickness 12 mm. Fitting material: Q345R, specifications φ610×14. S(Ⅱ) = 81.957; allowable value = 402.6 – acceptable. S(Ⅳ) = 117.52; allowable value = 475.8 – acceptable. Please note constraints such as hole spacing, material yield ratio, welding groove type, and inspection requirements. Acceptable (+19%). **********Results of hole reinforcement calculation********** Port N1: Hole in a circular cylinder. Calculation method: Analysis based on GB150-2011. Calculated pressure: 0.35 MPa. Shell material: Q345R, nominal thickness 12 mm. Fitting material: Q345R, specifications φ610×12. S(Ⅱ) = 91.478; allowable value = 402.6 – acceptable. S(Ⅳ) = 129.08; allowable value = 475.8 – acceptable. Please note constraints such as hole spacing, material yield ratio, welding groove type, and inspection requirements. Acceptable (+29%)
Sw6 is a magical software!
Are you expressing yourself? Is the software wrong? Is it still the standard that’s the problem? The new SW6 analysis method is based on GB150; the analysis method specified in GB150 includes certain restrictions, but there’s no issue with the software part
It has been indicated that \"the actual protrusion length of the connector is 95 mm, which is too short; it must be extended to at least 98.793 mm\" and also that \"the actual protrusion length of the connector is 95 mm, which is too short; it must be extended to at least 104.79 mm\"... Please pay attention to the applicable conditions of this analysis method.
Uh. . . . I want to ask whether it’s reasonable to take 12 thicknesses, or if there is some other better algorithm
But even when the length is increased, it only just meets the requirements; those with a thickness of 12 already meet the standards by 11%. Isn’t it more reasonable to use a thickness of 12? I’m a bit worried. Is there a better way?
This post was last edited by SDHZZXM on 2017-10-6 at 16:07. If you really want to figure it out, then disconnect SW6 and carry out careful calculations using the method described in 6.6 of GB/T150...
This post was last edited by zhangjuhua on 2017-10-7 14:22. Has the allowable stress shifted? Q345R 3-16mm is one grade; it jumps to a different grade at 18mm
Reinforcement isn’t enough at 16mm!
Yes, but it indicates that the elongation length is too short; if it’s too short, the analysis method may not be applicable. As for why, with thicker pipes of 12 and 14 mm in thickness, the remaining reinforcement area actually becomes smaller – this is a bit hard to understand
The reason for the takeover length is that the standards specify a minimum reinforcement height when using analytical methods; if the reinforcement height is insufficient, it is not acceptable even if the stress levels are within the acceptable range. You can take a close look at the report: as the thickness of the reinforcement increases, the stress value decreases, but the amount of reinforcement available is not sufficient. This indicates that the software takes into account both the height of the reinforcement and the stress value when generating its results. So if one wants to have a larger reinforcement allowance, it’s no problem to increase the wall thickness of the fitting while also increasing the height of the reinforcement; the allowance will definitely be greater in this case than when the thickness is smaller.