Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by PAstructural08

  1. PAstructural08

    openings on roof deck

    I would frame the opening out with channels or angles and attach the decking to those members (bolts, screws, welds, etc..). If you do that than the opening could be as large as required.
  2. PAstructural08

    MODELING BOX GIRDER IN STAAD PRO

    I don't believe staad has those kind of predefined sections. You can input the properties in the 'general' tab (define button) or perhaps go to the section database - tube - define your own tube size. No matter what you do though; staad will not be able to design the member. The best you...
  3. PAstructural08

    P-Delta analysis, notional loads and tension only bracing

    If using tension/compression only members you have to use repeat loads and NOT load combinations.
  4. PAstructural08

    Concrete Column Unsupported Length

    Sounds like the pier is also the column; is it continuous from the footing to level 2? If that is the case than both would be the unbraced length but worst case I think would be B. But you can only use the slab as lateral support if it is tied into the column with reinforcing.
  5. PAstructural08

    Square Tube or Rectangular Cross Section, and practical application

    Correct, if you were only worried of jackknifing (horizontal forces) than you would increase the width of the tongue.
  6. PAstructural08

    Square Tube or Rectangular Cross Section, and practical application

    First, I would say that the I value is not directly related to the stress/strength of the tube. When calculating deflections you would use I but when calculating stress you would use S (section modulus). That would be I/ybar; from your example above I=9.61.....S=9.61/2.5, where 2.5 is half of...
  7. PAstructural08

    Wind load on a single beam

    What is this beam being used for? A simple answer (for a single beam), I would use Fig 6-23 to calculate your force coefficient (Cf). Where your 'E' for a single beam would be unity (1) and using the formula for a square cross section Cf = 2.1.
  8. PAstructural08

    Wind load on a single beam

    I think you're still multiplying the pressure by the length; should be 21 psf x 2ft (W24x68 depth) = 42 plf = 0.042 klf. Also, that is a wind pressure; you should be using a design wind load. Take the velocity pressure and multiply that by a gust-effect factor and force coefficient (see...
  9. PAstructural08

    Wind load on a single beam

    Without know additional information the actual wind pressure could not be checked. You give a wind pressure of 21 psf so where does the 40 psf come from? Also, you shouldn't be multiplying the wind pressure by the length of the beam; it should be the design pressure x the depth of the beam...
  10. PAstructural08

    Double angle bracing connections in transmission towers

    Perhaps this is just me, but I find this post confusing (especially the first two sentences). I'm not to sure what your saying and what you are actually asking. Are you asking about the connection where the two double angles cross? What do you mean when you say "compound"? Some...
  11. PAstructural08

    Wind Turbine Foundation using STAAD

    I'm not to sure this will answer your question but I believe it is useful information. I have never modeled anchor rods in STAAD before; I have always had a support where an anchor rod would be and I would than take that reaction and design the rod/baseplate/shear lug/etc by hand or spreadsheet...
  12. PAstructural08

    Horizontal Braces taking vertical load...

    You are getting a instability because the entire structure is unstable; assuming you have simple shear connections and the bases of your columns pinned. You should keep the vertical braces active in the model. If the braces are simple x-bracing and are connected at a column and beam...
  13. PAstructural08

    Pulling out max brace force in a model

    I would recommend making the braces you want to look at a member group. After you run your model and go to post processing, pick the load cases you want and the range you wan (ranges can be individual member numbers, groups or properties). Than go to your beam tab, forces tab and than in the...
  14. PAstructural08

    Horizontal Braces taking vertical load...

    What program are you using? When you say 'gravity load' do you mean selfweight of the structure or do you mean just vertical load?
  15. PAstructural08

    Staad V8i - Multiple Support Conditions

    I don't believe this is possible. You could just change the supports in the same model as you need too and after your design is complete and final, copy the model with each support type. Anyway is time consuming. Good luck.

Part and Inventory Search