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Wood Lag Screw Design 2

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dik

Structural
Apr 13, 2001
25,740
The Canadian wood code CSA O86 has a table of coefficients for a JG value. Does anyone know how this can be calculated? A snap of part of the table:

Clipboard01_xaeqt9.jpg


Is there something similar to this in the US Codes? maybe with a formula?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
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dik - calculation of C[sub]g[/sub] (the group action factor in the NDS) is on page 80/206, section 11.3.6 of the document Phil1934 posted.
 
Thanks very much gentlemen... it the formulae that I need. I occasionally end up with someone spec'cing lag screws and I generally stipulate that the fastener and the attachment must 'work by others' (not my monkey, not my circus)... on the last project my client's client needed some help, so I'm writing an SMath program to do this. I had no idea that lag screws were as complicated as what they are.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
Wow...

Clipboard01_zr23yn.jpg


Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
And just think, a poorly placed knot makes it all moot.
 
Ya, I cannot imagine this detail for something 'so iffy'. Like masonry... statistically determine the strength to great detail and arbitrarily slap a factor of safety of 10... Engineering at times makes little sense. Caused by non-engineer, engineers writing codes.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
Measure with a micrometer, mark with a crayon, cut with an ax.
 
When I used to do fine woodworking, I used an exacto knife for a pencil...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
Does the NDS equation line up with table?
I went through this exercise awhile ago and called it a day by just having a "refer to tables" note on the sheet. I have the WoodWorks connectors program and only use my sheet to double-check numbers.
 
Don't know yet... will let you know and will post the SMath when completed.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
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