Aerowerx
Well-Known Member
My reason for looking at a composite/hickory sandwich for my landing gear is to save some weight.
I took another look at the Wilford landing gear design spreadsheet, being a more careful this time after having gained a lot more knowledge since my first attempt.
The Hickory gear does not look all that bad.
A steel gear that meets my requirements would weigh about 25 pounds, and aluminum about 17 pounds, while Hickory is about 10 pounds.
Previously I was watching the margin of safety values as I changed the parameters. This time I got the idea of looking at the deflection numbers instead, so long as the safety values were above 0.5 (FOS of 1.5, I guess).
I came up with (for Hickory) a static deflection of about 1.75 inches, and 6.25 inches at the reserve energy condition. Thickness is 1.5 inches, and tapers from 4 inches wide down to 2.5 inches at the axle. I plan on using twelve 1/8th inch strips of Hickory laminated. Then covered with 1 or 2 layers of glass for protection.
I have previously done an experiment on some Hickory laminations. By alternating the grain directions the Modulus of Elasticity comes out almost exactly to the theoretical value.
Sounds amazing, and I would like someone else to verify it. And I will do some number crunching myself with the basic formulas
I took another look at the Wilford landing gear design spreadsheet, being a more careful this time after having gained a lot more knowledge since my first attempt.
The Hickory gear does not look all that bad.
A steel gear that meets my requirements would weigh about 25 pounds, and aluminum about 17 pounds, while Hickory is about 10 pounds.
Previously I was watching the margin of safety values as I changed the parameters. This time I got the idea of looking at the deflection numbers instead, so long as the safety values were above 0.5 (FOS of 1.5, I guess).
I came up with (for Hickory) a static deflection of about 1.75 inches, and 6.25 inches at the reserve energy condition. Thickness is 1.5 inches, and tapers from 4 inches wide down to 2.5 inches at the axle. I plan on using twelve 1/8th inch strips of Hickory laminated. Then covered with 1 or 2 layers of glass for protection.
I have previously done an experiment on some Hickory laminations. By alternating the grain directions the Modulus of Elasticity comes out almost exactly to the theoretical value.
Sounds amazing, and I would like someone else to verify it. And I will do some number crunching myself with the basic formulas
