Interpreting a Stress - Strain Curve

[christian Bendis]

Hi all

I was wondering if someone could help shed some light on interpreting a stress strain curve (attached).

It appears that two timber types (soft and hard wood) were loaded parallel and perpendicular to the grain and the stress strain curve produced.

I am trying to make sense of it.

So far i can say that:

loading parallel to the grain for both wood types results in a steeper stress/strain curve thus the young's modulus is greater when loading parallel to the grain, thus the material is stiffer.

I was struggling to make any more sense out of it and i was wondering i could get the opinions of the community?

Thank you.

[Cragyon]

Yes, rated stress of wood is dependent on loading direction relative to grain. Loading perpendicular to grain will cause separate.

Also, the stress strain curve is incomplete.