Iso 12215 curvature correction factor

I was just wondering about the curvature correction factor Kc. Can you use it for all panels regardless of the short span direction or can you only take it into account if the curvature is in the short span direction?

 

I am surprised of the question.

The curvature to use for Kc (panel) is the curvature in the short direction. There is no doubt about it in the rule.

The only problem is if you have kind of conical panel, with rather different curvature in the short direction at both ends of the panel, or kind of kayak bottom, transverse curved at both ends, but rather flat in the middle.


The panel curvature in the l (long) direction will of course be used for Kcs, for the corresponding stiffener.

 

Sure yes I understand. The equation wouldn't make sense otherwise. I just think this is not realistic as you only have to change the size of the panel a fraction before you can't take curvature into consideration. A tiny change but a dramatic effect on strength requirements.....

 

I still do not see the point.

Kc=1 from 0 to 0.03.

Kc =.5 above 0.18.

And between 0.03 and .18, it is a straight line between the 2 values (0.03,1) and (0.18, 0.5).

I do not see a dramatic effect if you change panel curvature.

 

Well on bending moment, it is a squared function in the ISO rules. 1 squared is 1 and 0.5 squared is 0.25. 1/.25 = 4 . So yes, 4 times the bending moment required is pretty dramatic