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Connection design per NDS

Connection design per NDS

Connection design per NDS

(OP)
Does anyone know if there exists software for calculating connection capacities per NDS? I'm specifically interested in dowel type connections (nails, lags etc) though something comprehensive for all connections would be welcome... Thanks

RE: Connection design per NDS

Yup.

Link

RE: Connection design per NDS

(OP)
Nice. How about TEKS screws?

RE: Connection design per NDS

For cold formed studs, I check TEK screws with a spreadsheet. For wood, spec the Simpson SDS wood screws. They have load tables for them and no pre-drilling required.

RE: Connection design per NDS

mike, (in my earlier days) I've designed many, many spreadsheets to assist my calcs.

I specify TEK screws weekly.

I'm struggling to imagine how you would design a spreadsheet for TEK screws.

HOWEVER - I don't know how you could explain it without a visual, AND i do NOT desire to violate ethical etiquette. SO - respectfully, perhaps this may remain a mystery to me.

I can't help but think that such a spreadsheet would be either so simple (that i'd smack my forehead) or extremely complex considering all the possible, practical parameters.

If you're able and willing to share, i'm curious.

If you prefer not, i respect the decision.

If this is an unethical request, please forgive me and have a wonderful day!

Thank you!





RE: Connection design per NDS

I should have elaborated rather than just blindly spewing that I have a spreadsheet that checks TEK screws, which was obviously misleading. What I should have said is that I have a spreadsheet that does the basic calcs of TEK screws in cold formed studs: screw shear, pullout, pullover, and screw tension (nothing special with these calcs). I felt that was basically what the OP was looking for, but I may be wrong. So yes, it is extremely basic; sorry for being so misleading. I agree that considering all the possible, practical parameters would lead to a complex, cumbersome spreadsheet. Often times I don't find myself in a position that I have to check that many complex situations, so it works fine for what I need.

RE: Connection design per NDS

(OP)
It seems from this exchange that no TEKS specific software exists, but that we can use the AISI manual to perform some (though not all) of the checks. In that case, is there a generic (non-proprietary) screw type that is very similar to TEKS screws (which, it seems are proprietary) for which there might be software?

Just to let you guys know, I have started developing my own spreadsheet and it can do some AISI checks but it will be a long time before I develop a comprehensive understanding of these things. Meanwhile, it would be good to have a quick and dirty way to check TEKS screws that are subject to conditions outside the scope of the ESR report...

RE: Connection design per NDS

AISI has all of the equations. The only thing needed specifically for TEKS screws is the nominal strength of the screws, Pts and Pss, which is published in TEKS ICC ESR. The actual strength of the screw doesn't govern until fairly thick sheet metal is used.

RE: Connection design per NDS

(OP)
Actually, wannabeSE, the pullover, pullout and shear (bearing) loads are also obtained from testing. You basically can't (unless you wanted to get incorrect values) use AISI to check TEKS screws. The whole point of the ESR report is that they are using the AISI provision that allows you to substitute their equations for proper testing values. Please see another specific thread I started: http://www.eng-tips.com/viewthread.cfm?qid=411037

RE: Connection design per NDS

I don't know why TEKS Select screws use tested values instead of calculated per equations in AISI. Regular TEKS screws use calculated values in ESR-1976. I would only be guessing if I tried to answer why the TEKS Select is different from other screws with ESRs. Sounds like a good question to ask ITW Buidex.

The tabulated values in the TEKS Select ESR are limited to a few applications with Fu = 58 ksi. It may be good for A36 and conservative with typical 16GA and thicker studs (Fu = 65 ksi), but won't work for typical studs less 16GA (Fu=45 ksi).

Provided the screws meet the requirements in AISI, I don't know of anything that prevents you from using the calculated values. The tabulated (tested) values in ESR-3223 are odd, why does a 1/4-14 have different pull over capacity than a 1/4-20 with the same head? My guess is scatter from a limited number of tests.

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