Is it a coincidence that the calculation formulas for the effective height of the opening reinforcement and the height of the straight edge section of the WN flange are similar?
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The last edit to this post was made by Claymore2000 on 2024-12-11 at 08:22. Dear teachers, regarding the calculations for WN flanges, the formula h/h0 = h/√(dop*δnt) is used. In GB/T150, only the formula for h0, namely h0 = √(Di*δ0), is provided; its physical meaning is not explained. Later, through an article on a public account, it was learned that h0 = √(dop*δnt) represents the minimum length of the straight edge required for long-neck flanges； Recently, while studying*, I noticed that the formula for calculating the effective height of hole reinforcement, h=sqrt(dop*δnt), has a structure similar to that of the formula for the straight edge section of a flange, h0=sqrt(Di*δ0). In both cases, it is a square root of (inner diameter*wall thickness). Additionally, both flanges and hole reinforcements are subject to secondary bending stress. Therefore, I wonder if this similarity between the two formulas is coincidental Or is it because the computational models and the problems being solved in both cases are similar, which leads to similar structures for these two formulas?
The formula sqrt(Di*δ0) is essentially another way of expressing the stress attenuation range sqrt(R*t); the two have different calculation principles
It is not a coincidence that these two formulas are similar; rather, it is due to the common mechanical model and similarity in stress distribution underlying them. In reinforcement, both of these structures involve the influence of the inner diameter (dop) and wall thickness (δnt) on the overall stiffness and strength. Both the effective height of the perforated reinforcement and the height of the straight edge section of the WN flange need to withstand certain stresses in order to ensure the stability of the structure; this results in structural similarities in their design and calculation methods. Therefore, this similarity reflects similar mechanical requirements and design principles. .