Yes, I am suggesting moving the doubler layer in your drawing all the way up into the apex to add thickness there. If at that point the webs buckle then making the entire spar from thicker material with lightening holes and/or adding stiffeners may be your answer.Poormansairforc
Are you suggesting, to just double or add to the thickness at the apex with no space ,no box.?
Norm, it's obvious that bumblebees can fly; any tales of math saying otherwise are urban legends. It's also obvious that your plane can fly and that the spar didn't fail in flight... yet My point is, for how long? Your post about fatigue and stuff and GA planes being somehow different, though, is incorrect. An ultralight is lighter and flies more slowly, yes, but the laws of physics are exactly the same.The spar I made for my UL and the rest of the make up of the wings, I made were and still are fine for a UL . IT could go on flying long after I am gone. And The Dana's of the world will keep saying bumble bees cant fly because the math says they cant.
Hi Norm,...Would 2024 make the grade for a cantilevered wing with the arm load so high. Maybe not.
The math tells me the cable probably isn't the weakest link. But this is why I encourage you to learn about basic stress analysis concepts. A strut braced wing does indeed have shear stresses both inboard and outboard of the strut attach point... though I'm not sure, what you're calling "shear" may be bending moments?Dana
The flying wire changes how the wing is built and what from it also changes the Direction of the load. Out board of the wire the arm being shorter less shear load . Inboard of the wire no shear. The G load is then transferred to the Wire or struts,depending on the point of attachment, whether it becomes a fulcrum then the root would be Compression and down on the root attachments. My plane,the inboard load be comes compression and less shear. This allows for simple hardware fasteners at the roots.
Like all other strut supported aircraft my plane will never come apart unless the wire fails (strut failure)
Speculating if the wire were to part the wing may or may not destruct it may only bend there by, becoming crippled but still flying. Any other type aircraft with a strut failure your done.
Each single cable is rated for 2000 lbs the GV of the plane is 520 with fuel and a 170 pilot. What does the math tell you ?
It would not need the square tubes.If a spar tube of 6 inch dia. .050 wall had 3 , 1X1 square tubes riveted to it in thirds the way around it. would it be a triangle or a round spar ?