Where I can find the formula?
Where I can find the formula?
(OP)
Hi
I have to design a railroad hinge tip wooden crossing gate. Must be 28'. How do I calculate where should I install a small beams between two arms? And how calculate the pressure from wind on those arms?
Thank You
I have to design a railroad hinge tip wooden crossing gate. Must be 28'. How do I calculate where should I install a small beams between two arms? And how calculate the pressure from wind on those arms?
Thank You





RE: Where I can find the formula?
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RE: Where I can find the formula?
Frankly, I'd go measure two or three: Don't bother re-calculating how round a wheel needs to be if you don't have to. Also, you may see other "small solutions" on the operable units that are there to solve problems you haven't thought of yet.
Wind load? The vibrating, moving weight of a thin 28 foot lever-mounted as it is pulled up and down will override pure wind loads on a 4 to 6 inch wide flat plate. That is: the twisting force sideways from wind will be small compared to the force from gravity and the dynamic moving forces of the lever. So once you've mounted the boards to the pivot arm - say, perhaps with four 1/2 diameter galvanized through bolts in a rectangular pattern around the pivot block - the wind load will be resisted very adequately.
RE: Where I can find the formula?
RE: Where I can find the formula?
RE: Where I can find the formula?
RE: Where I can find the formula?
Find the frontal surface area being hit by wind.
the solve for the resultant force of this:
Cd=(drag force)/(0.5*(Specific density of fluid)8(V^2)*(Asurface)
where,
Cd=Coefficient of drag, you can approximate this to a general shape and get a value from any fluid mechanics book.
V=velocity of wind.
You have all parameters, so solve for "draf force"
Once you find the Force use this to calculate the bending moment or stress on your structure.
the equation works fairly accurate, compared to a CFD analysis or real life testing.