Transverse frame calculation

Hello,

Can I submit you an example of calculation for a transverse frame for a sailboat with ISO 12215-5 ?

The boat had a Lwl of 9 m and a displacement of 6500 Kg, built in steel. The frame space is 0.60 m : I assume (see sketch under) that l = 2.20 m, c > 0.18 l and that the point "P" is under the waterline.

I take the minimum bottom pressure (0.35 Disp^0.33 + 1.4 Lwl = 19.13 kN/m². The allowable stress is : 235 * 0.8 = 188 N/mm². The curvature factor is 0.5 (as c > 0.18 l).

SM = ((83.33 * 0.6 * 2.2² * 19.13)/188) * 0.5 = 12.35 cm^3

Is my reasoning correct ?

Thank you in advance

Best Regards



Jacques

 

That is what I get with my program SCT.
Best Regards
Ignacio López

 

Hello Ignacio,

Thank you very much for your answer.

In fact, in my question, I had supposed that the crown stiffener is 18 % of the unsupported length, so the Kcs is 0.5. If I correct your figure for frame SM (19.96 * (0.5/0.827), we are agree.

But how do you calculate the base bottom pressure of 31.8 kN/m² ?

Best Regards


Jacques

 

Yu are right, Jacques.
See new file "Ducruy-1.doc", in previous post.
B.R

 

Thank you very much

BR


Jacques

 

I am new to design.
How can i learn to read rule Llyod's for what is meaning between 2,5H and 7,5H????
Can somebody help me.