Rig computations ?

[TANSL]

Once converged, it is a simple matter to check sectional compression and buckling.

On shrouds?, no, that can't be correct.
I don't understand why you need to take the mast into account to get the shroud loads, but I really don't understand your reasoning so I'm going to put the subject on hold until I can acquire enough knowledge to understand you. Thanks, anyway, for your explanations.

 

[jehardiman]

On shrouds?, no, that can't be correct.
I don't understand why you need to take the mast into account to get the shroud loads, but I really don't understand your reasoning so I'm going to put the subject on hold until I can acquire enough knowledge to understand you. Thanks, anyway, for your explanations.

You are correct in that I'm not being clear. Shrouds are always in tension and cannot buckle. Shrouds and their attachment points fail only in tension Stayed masts however, assuming no shroud failure, fail by either Euler buckling (a sectional property loss of columnarity) or compression yield caused by the shroud load (axial) or spreader load (transverse) including superposition of those loads from truck to step. Since you can fail the system either by having the shrouds too strong and the mast too weak or the reverse, the mast must be considered when designing the shrouds. Especially if the goal is to minimize weight aloft.

 

[TANSL]

What I mean is that shrouds are calculated without regard to which mast they are attached to. On a normal rig you don't need to know what the mast looks like. Once the forces on the shrouds have been calculated, the components that act on the mast can be known and we can calculate its mechanical properties (even if the goal is minimize weight aloft).

 

[gonzo]

Considering that it is not a masthead rig, there will be a force to leeward on the masthead. That would make the shroud opposite to D2 to be in tension. However, with pre-tension that force needs to be added.

 

[fcfc]

Hello,

jehardiman is fully correct. I currently doing my "homework".

The classical method of rig sizing makes a bunch of assumptions to have something easily computable. No shrouds or mast deformation. Mast rigidity in bending negligible compared to rig geometry rigidity. (ie force on shrouds is the same, whatever mast section, keel stepped or deck stepped). And when you change geometry, simplifications are no longer valid or pertinent.