Human Powered Plane Spar Problem 1

[JamesOconnel]

I'm studying manufacturing engineering in Ireland and I've been assigned a project in which I've to design a spar of a human powered plane. The objective being to make it as light as possible however stiff enough to maintain aerodynamic efficency. My main considerations have to be in relation to in-service performance and failure (yield, fracture and fatigue strengths)

The material(s) I choose and the section shape are my variables.

Any information I find in relation to this subject is fairly old, I would greatly appreciate it if someone could point me in the right direction to a good website or textbook, especially where the stresses are concerned.

Thanks in advance of any advice.

 

[zerosum]

You probably already know, anything by McReady.

 

[JamesOconnel]

Yeah I've looked at macready's work.

Thanks anyway

 

[rb1957]

i haven't, but doesn't he go over his sotry about building a successfull man-powered plane. i doubt he gives away many of the technical details, but you can see his design, and you know some of why he made it that way, and you should be able to reverse engineer it and adapt it for your unique situation (i'd guess that your project is trying to achieve something different to his, so his solution might not be right for you)

 

[zerosum]

brozy,

Maybe a search on the Kramer Prize (1970's) and it's offshoots. There was quite a bit of work going on in the UK as I remember.

A couple of associates and myself (a good aircraft structural and an aero and me, a skinny test pilot at the time, spent a few hours over brews (in New Mexico) discussing possibilities.

Wonderful subject, good luck...

 

[zerosum]

A related field would be hi-tech composite sailboat masts.

http://www.sailboat-technology.com/links/online_articles.php

 

[zerosum]

Fracture mechanics and fatigue of modern laminates are discussed in the (freely accessible) papers by Eric Greene Associates, Inc at the above link.

NASA likely has linke to similiar jnformation

 

[JamesOconnel]

Thanks for the link, the papers by Greene are really useful for the yield, fracture and fatigue strengths of composite materials. I woundn't of found it on my own.

Go raibh mile maith agat
Brozy

 

[Compositepro]

Wing spars on human powered craft are usually tubes made from high modulus carbon fiber. Nothing else can compete in the stiffnes versus weight category. These will be very fragile. There is no getting away from the fact that anything that is very stiff and very light will be fragile. Safety margins add weight and with human power you cannot fly if you are too heavy.