MrOlive
Nuclear
- Feb 24, 2012
- 1
Hello,
I am doing a shell buckling evaluation per code case N-284-2. The cylinder is considered immersed in water at a 290 psi. After doing the evaluation with no stiffeners I did not pass the relationships of -1713, and since my thickness is fixed I started messing with stiffeners.
The constraints are that I can't use rings. So I'm using stringers (internal). Just to make sure I understand (english vocabulary - sorry, I'm French): stringers would be straight longitudinal stiffeners, parallel to the cylinder axis, is that correct?
I want to make sure I understand -1200 correctly, especially the terminology and definitions. For example: l_i (= "l index i", so that's either l_phi or l_theta). l_phi is going to be the distance between ring stiffeners and l_theta is going to be the distance between stringers, is that correct? So let's say, for example, that I have no rings and 2 stringers: l_phi is going to be about the length of the cylinder and l_theta is going to be half of its inner perimeter?
How about l_si? It's defined as "one-half of the sum of the distances l_i on either side of an intermediate size stiffener". I must be missing something because the way I see it there is one l_i on either side of the stiffener, so the sum of the distances l_i on either side of a stiffener is always going to be 2 x l_i, so half of that is l_i, and therefore l_si would always be equal to l_i? I must be missing something obvious here...
Thanks for any help anyone can provide...
I am doing a shell buckling evaluation per code case N-284-2. The cylinder is considered immersed in water at a 290 psi. After doing the evaluation with no stiffeners I did not pass the relationships of -1713, and since my thickness is fixed I started messing with stiffeners.
The constraints are that I can't use rings. So I'm using stringers (internal). Just to make sure I understand (english vocabulary - sorry, I'm French): stringers would be straight longitudinal stiffeners, parallel to the cylinder axis, is that correct?
I want to make sure I understand -1200 correctly, especially the terminology and definitions. For example: l_i (= "l index i", so that's either l_phi or l_theta). l_phi is going to be the distance between ring stiffeners and l_theta is going to be the distance between stringers, is that correct? So let's say, for example, that I have no rings and 2 stringers: l_phi is going to be about the length of the cylinder and l_theta is going to be half of its inner perimeter?
How about l_si? It's defined as "one-half of the sum of the distances l_i on either side of an intermediate size stiffener". I must be missing something because the way I see it there is one l_i on either side of the stiffener, so the sum of the distances l_i on either side of a stiffener is always going to be 2 x l_i, so half of that is l_i, and therefore l_si would always be equal to l_i? I must be missing something obvious here...
Thanks for any help anyone can provide...