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Recent content by Grizzman

  1. Grizzman

    Draftsight 2019 - no longer Free

    Yesterday (2/16) still using copies of DS15 and SD18 without issue. On my 15 version, I get the reaactivation message saying it is going to expire. I figure that is how they will get people off it. I will try registry edit to see how long it lasts.
  2. Grizzman

    Draftsight 2019 - no longer Free

    Today is 1/3/20. I just opened my free version of DS18 without a hit. did a print, a save, and a save as without issue. Will it last? I don't know. just wanted to pass that along.
  3. Grizzman

    Stair Tower Design

    If it is a means of egress from the building, I'd have to go with chapter 12. If it's just a way to access a roof for periodic maintenance, chapter 15.
  4. Grizzman

    Plate Girder

    I argued with an architect one time about the underside of an awning at a grocery store. What he wanted cost 3x what was needed. He won the argument. I'd have to say the owner lost.
  5. Grizzman

    Plate Girder

    My degree is architectural engineering. I can appreciate what an architect is trying to achieve. He(the architect) just usually doesn't see the innate difficulties in achieving his dream. add a couple of outcroppings and returns to a box. you still have a box but now it has texture. It's amazing...
  6. Grizzman

    Natural frequency in ASCE question

    I hadn't tried adding nodes into the model. to me, it's their(RISA's) biggest shortcoming. p-little delta can not be accurately modeled with less than about 20 sections on a column. thanks for checking it out. In empirical units w/g = slugs. That's pretty much what was stumping me in the first...
  7. Grizzman

    Natural frequency in ASCE question

    Bah! I wrote the unit resolution wrong. right answer, I just didn't drop the square from the second after taking the square root. Sorry about that.
  8. Grizzman

    Natural frequency in ASCE question

    It was easier(or quicker, at least) to post the hand written solution. If anything needs clarification, let me know.http://files.engineering.com/getfile.aspx?folder=89fe5670-e143-4659-b672-3f3d40ad3797&file=frequency__resolution.pdf
  9. Grizzman

    Design of Coped Gusset Plates

    I always boggles my mind when engineers leave one of the most critical links of the structural system up to someone else to design. Often that other person is not an engineer or is an engineer with very limited knowledge of all the forces going into the connection. I'm not saying you shouldn't...
  10. Grizzman

    Diaphragm Tributary

    While his diagram shows fixity at the bottom, both his equations imply pinned at the base. I don't believe his intent was to fix the base. How much good will a <=3' wide footing do in that situation.
  11. Grizzman

    Natural frequency in ASCE question

    Yes that is exactly what I did. It is tedious to convert everything over to metrics however. After I found my answer (8.7 Hz), I backed that out in english units. mass is given in slugs. Of course it didn't match the RISA results (6.3Hz), but both at way over 1 so I'll just go with Gf=0.85...
  12. Grizzman

    Natural frequency in ASCE question

    I understand where the 386 comes from.(gravity in in/sec^2) What I am asking is for clarification as to why you're ignoring the empirical conversion factor. In English units: lbf=lbm*a/gc or lbf=slug*a a slug = 32.174 lbm. to further clarify: 11.96lbf*0.225=53.2N /9.807(acceleration due to...
  13. Grizzman

    Natural frequency in ASCE question

    I follow your equation. could you explain why you're only multiplying by 32.174 and not dividing by 32.174 also? one is acceleration due to gravity, the other is G sub c, an empirical conversion factor to convert pound force to pound mass. Thanks for your efforts.
  14. Grizzman

    Diaphragm Tributary

    TA=24^2/2/20 Unless you're doing some kind of unique design, the wall reinforcing will make the wall act as a cantilevered beam. pinned at bottom and at roof. Now if you're tying bars into the roof or in some other way making the roof a moment connection, then all bets are off.
  15. Grizzman

    Natural frequency in ASCE question

    F=m*a/gc therefore m=F*gc/a 11.96(lbm/ft)=11.96(lbf/ft)*32.174(lbm-ft/lbf-sec^2)/32.174(ft/sec^2) 11.96*32.174=384.8 (close to what you said) but why don't you divide by acceleration due to gravity to get pure lbm? You've got to love the english units. . .

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