Mechanical properties for woods.

[Thorvald]

Hi.

It is relative easy to find mechanical properties for woods that can be used in building construction. But I would like to find mechanical properties for woods that can be used in bow building. That would be properties for woods such as hard rock maple, yew, bamboo, cocobolo, bolivian rosewood, bocote and such. And an additional question is: What material properties determines if a wood is good as a spring, i.e. when it is bent and released it returns to it's rest position as fast as possible.

Below is some examples of woods from a book I have.

By the way - I think "Pokkenholt" is Lignum Vitae.

 

[Studiot]

You might find more help in these specialist places.

http://www.archery-interchange.net/forum/

http://www.archery-forum.com/

http://sagittarius.student.utwente.nl/bb/

 

[Thorvald]

Maybe, but I doubt it. I am on AIUK (the first link). The two other fora is rather unknown to me. But in general archers and even bow builders (as far as I know) doesn't know the mechanical properties of the woods they are using. Because they go by experience: If the limb is so and so thick, and made of this wood, it gives a draw force of XX lbs. But I'd rather like to go the more scientific route. The closest to something that I might be able to use is this: (Well couldn't get the link, the site didn't work. But it is at www.binghamprojects.com. I have attached it. But this is for the bow as a whole and probably with laminations and with fibreglass. Also it doesn't mention what bow woods the chart is based on.

 

[dipstik]

modulus pertains to springiness (hookes law) and tensile strength, or even better, flexural rupture will give u an idea of how much it can bend.

I think ASTM D143 has proceedures to determine these values, so u might want to use that as a google scholar search termgood luck