Ultimate Capacity of Southern Pine
Ultimate Capacity of Southern Pine
(OP)
Friends:
I have got a design problem where I need the ultimate shear stress of Southern Pine to estimate shear capacity of a pile made of Southern Pine. I went through several codes and manuals, I could only find the allowable stress. If you know any reference where I could get this information, I really appreciate you.
Thanks,
N.S.
I have got a design problem where I need the ultimate shear stress of Southern Pine to estimate shear capacity of a pile made of Southern Pine. I went through several codes and manuals, I could only find the allowable stress. If you know any reference where I could get this information, I really appreciate you.
Thanks,
N.S.





RE: Ultimate Capacity of Southern Pine
I tried to contact various NDS code writing officials some years ago and only got 1.6 to 2.0 as the "safety factor" built into the NDS values.
RE: Ultimate Capacity of Southern Pine
RE: Ultimate Capacity of Southern Pine
For shear, a good value for ultimate strength is even more elusive. Probably the best available is "Shear Strength Parallel to Grain". Again, this is based on small-scale tests under optimum conditions.
The values that JAE has offered (allowable stress has a 1.6 to 2.0 safety factor) are very good, but are most likely based on the elastic limit, not the ultimate strength.
IMHO (and that is all, just an opinion), when EXCEEDING the elastic limit for a "real" field application my best guess at "ultimate strength" is 4 to 6 times allowable bending stress and 4 to 6 times allowable shear stress.
Of course, exceeding the elastic limit means that the members may be "worthless" for structural purposes after these loads have been applied (assuming they survive at all).
A final note, your problem is even more hard to pin down since "Southern Pine" can be any one of a number of species with differing properties.
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RE: Ultimate Capacity of Southern Pine
RE: Ultimate Capacity of Southern Pine
I'll see if I can dig it up next week.
It may not be accurate, though, because I don't remember any of the numbers approaching 4-6 except for the lowest grade lumbers (were around 3).
RE: Ultimate Capacity of Southern Pine
Thank you so much for the responses. But, I have another question related to the same topic.
If I want to find the ultimate horizontal shear capacity of pile (force acting horizontal),can I use the ultimate shear strength (parallel to grain). is shear strength in any direction the same?
Please give me your thoughts.
Thank in advance
N.S.
RE: Ultimate Capacity of Southern Pine
RE: Ultimate Capacity of Southern Pine