rynhardt wrote: ↑
Sun Jan 14, 2018 10:39 am
Sun wrote: ↑
Fri Jan 12, 2018 11:37 pm
Thanks for the shear and moment diagrams!
Let me rephrase then: The load (water pressure) is the most evenly distributed, and the reactive forces are mostly symmetrical around the centre, which implies that the forward half of the board doesn't work any harder than the back half. is
Unless someone wants to volunteer to do a plate analysis I'm going to assume the short axis can be treated as uniform across the entire board.
The water pressure is not evenly distributed and no, they are not symmetrical around the middle. The pressure is linear because the board is under an angle in the water, length wise.
Edging harder, bigger linear water forces.
Look at the perspex. The left side is above water, where is the water pressure on that part? I would argue that on this pic, the water line is in the middle, no? So the forces are linear from the middle to the tip, with the biggest on tip.
Water pressure is linear from depth to water surface where is zero, not uniform.
The problem is, as I mentioned, the support is not fixed, but free. Ok, for the sake of discussion, one support can be fixed, but than, the other one is free (left side on this pic). Free as left foot
So the red line on the diagram does not represent the board when riding. Plus, non uniform i-beam, etc.
Second diagram, Savitsky:
This is a plain board ride against the water, not edging. Not sure what is this proving when we just do not ride a TT that way 99% of time.