NDS Connection Lateral Design Values
NDS Connection Lateral Design Values
(OP)
I'm trying to reporduce Table 11L from the 2001 NDS For Wood Construction. I'm using the Yield Limit Eqations found in Table 11.3.1A but can't come up with the same values listed in Table 11L. If I understand the code correctly, the minimum value obtained using the 6 formulas should be what is listed in the table. Am I reading this correctly? If so does someone have an example that shows the correct results for values found in the table? Any guidance is appreciated.






RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
Be sure to read all the footnotes (I know you said you did above) and hand check the calcs if you are using a spreadsheet. Sometimes there could be a mixed unit issue within the equations.
RE: NDS Connection Lateral Design Values
It might also have to do with whether you have rolled threads or full body threads. Compare the 97 NDS to the 2001 NDS values for lags. The 2001 values are for reduced bogy lags.
RE: NDS Connection Lateral Design Values
The example I used is #8 wood screw, D = 0.164", Table 11.3.1B D < 0.25" therefore Rd = Kd = 2.2 for D ? 0.17"
Wood is southern pine, Gm = Gs = 0.55 therefore Fem = Fes = 5550 psi
ts = ls = 1/2", I assumed tm = p = 10D as per Table 11L note 2 therefore tm = lm = 1.64in
Fyb = 90,000 psi for D = 0.164", Table 11L note 2
Zmin = ZIIIs = 119.7 lbs... Table 11L Z = 91 lbs.
Probably something real simple I'm missing but I'm missing it.
RE: NDS Connection Lateral Design Values
I think the difference is that the tables in the 97 NDS are based on cut thread wood screws & the tables in the 2001 NDS are based on rolled thread wood screws. See appendix L of the 2001 NDS.
If you look at the tables for lag screws you will find that the 2001 NDS is based on reduced body diameter lag screws while the 97 NDS table is based on full diameter lag screws.
RE: NDS Connection Lateral Design Values
Nothing obvious to me about the discrepancy.
RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
RE: NDS Connection Lateral Design Values
The AWC table appears to subtract the tapered tip of wood screws. Based on Section 11.3.4 of the 2005 NDS it would appear that if the lag or screw penetration exceeds 10D that you aren't required to subtract the tapered tip.
In the past when calculating penetration for lag screws you subtracted the tapered tip, but when calculating the penetration for screws you included the tapered tip.
Thank you mpoint for this post I learned a lot as I was trying to help you with your problem