Thread: Physical properties of timber

What do you need this information for?

The way the "fm,k", "ft,k" etc are written is a bit misleading as the "m, t, k" should be subscripted. i.e. f_t,k

Anyway, a search of the web should reveal all e.g. have a look at page 5 of this document http://211.167.243.154:1012/file/gwb...20338-2003.PDF

Here are some unit converters:

Metric Conversion Chart, Unit Converter, Metric Conversion, Metric Units, Metric - EngNet
Unit Conversion - Online Unit Converter

Originally Posted by Runge

Here are some unit converters:

Metric Conversion Chart, Unit Converter, Metric Conversion, Metric Units, Metric - EngNet
Unit Conversion - Online Unit Converter

Now how did I know you would bite on this??!!

Originally Posted by BobL

What do you need this information for?

Many thanks Bob, that was exactly what I was after.
These numbers are needed to attempt to make a fiberglass tube equivalent in flexion strength of that of a timber pole of the same diameter. The question is how thick the fg should be.
Thanks Runge, I had a go to the conversion page. Is there, where I've got the directions for converting N/mm^2 to Kg/mm^2. I only wanted to make sure I got it right.
Cheers.

I thought it might be of interest to someone else so here are the numbers and the meaning of the abbreviations:

timber propery.png
4 Symbols and abbreviations
E0,mean mean characteristic value ofmodulus of elasticity parallel to grain (in N/mm2
)
E0,05 5-percentile characteristic valueof modulus of elasticity parallel to grain (in N/mm2
)
E90,mean mean characteristic value ofmodulus of elasticity perpendicular to grain (in N/mm2
)
fc,0,k characteristic value ofcompressive strength parallel to grain (in N/mm2
)
fc,90,k characteristic value ofcompressive strength perpendicular to grain (in N/mm2
)
fm,k characteristic value of bendingstrength (in N/mm2
)
ft,0,k characteristic value of tensilestrength parallel to grain (in N/mm2
)
f t,90,k characteristic value oftensile strength perpendicular to grain (in N/mm2
)
fv,k characteristic value of shearstrength (in N/mm2

I'd suggest that Euler's wall buckling theorem will the solution, to matching a hollow fiberglass tube properties to those of a timber mast or spar.

Buckling - Wikipedia, the free encyclopedia

Modulus of elasticity and strain to failure ratios (in compression and tension) of each material will dictate the required composition and thickness but also layup of the glass cloth - whether using woven rovings or CSM or combinations of the above.

F/glass (S2Glass) from memory is somewhere near 6% S to F ratio...

Some of the light weight high modulus graphite's are closer to 1% or less (0.95%) etc.

Timber will depend on species and dimensions but Id suggest it might be more than F/Glass..... going on some bamboo fly rods that I've cast compared to fiberglass and carbon graphite fly rods.

The bamboo are like spaghetti noodles to cast - in comparison to the more modern materials lending me to imagine that the timber S to F ratios MIGHT be similar too or even better possibly than F/glass.

As always, others mileage will vary.

Originally Posted by artme

Now how did I know you would bite on this??!!

Those websites are very useful, even if you're not an engineer. I finally had an excuse to post them.