stress interaction factor? 1

[structuralaggie]

I have the fifth edition of the AITC timber construction manual and while designing the tapered end of a glulam I came across a CI factor, called the stress interaction factor. To the best of my knowledge, this factor is not in the NDS. If I have just missed it, someone please tell me.

I usually only use the NDS for wood design and look at the AITC sometimes, primarily because I thought they basically had all of the same info. Is there other contradictory or extra stuff, besides examples, that is in the AITC manual and not the NDS? I just haven't been through it enough to know and may be something I need to spend some time on.

 

[woodengineer]

Structuralaggie:

I am not near my references, but I believe Ci is the Bearing Incising Factor.

woodengineer

 

[structuralaggie]

I know. Ci is actually in the NDS. This is C with a capital I and was called the stress interaction factor. I have never heard of it before.

 

[RARWOOD]

The NDS in section 5.4.1 requires that curved members having a varying cross section and taper cut glulams, be design according to Reference 52. Reference 52 is the AITC manual.

Generally for glulam, arches, pitched and tapered curved beams and beams of varying cross section the design procedures are only found in the AITC manual. The above members all require special designs. Not every thing can be included in the NDS.

Requiring design according to AITC is similair to the requirement to design metal parts in accordance with applicable metal design procedures. The NDS refers you to the AISC manual & the AISI manual for design of metal parts.

The CI factor accounts for the interaction of bending stress, shear stress and compresive stress in a tapered section. See section 4.2.9 of the AITC manual.

 

[structuralaggie]

Thanks.