Not that hard at all. Why do you need it ?
Simply because I am ways faster to do it with FEM than any other method (using FEM does not automatically mean you need 10000 elements). Second reason to do it, is because the next question is "and in the forestay?", and then "down wind?" and then "under spinnaker?".... see the questions here
But for the downwind case, I would say that the wind forces are what come to play, and the angle of the shrouds becomes a big amplifier of the force in the forward direction. Similar story for the forestay, it´s the mostly the will wind that determine the stay tension. Which is the worst case?
Actually the main sheet tension causes the highest loads in the fore stay (up wind), not the wind. If you sail with spi, then the shrouds can see "peak loads", if you forget to tension the main sheet.
The safety factor for steel wires can be smaller than 3 to 4. I guess the high figures avoid the need to calculate dynamic loads, which can be very important.
yes and for the not using of cosine law in the simple formula and for fatigue.
Cheers,
Klaus
