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 3dboy

  1. 3dboy

    Chinese Structural Shapes

    Thanks everybody for your help, I downloaded STAAD, couldn't figure out how to lift out their shape database. I wound up just entering everything into a spreadsheet by hand. It didn't take that long, and I would probably have wasted more time continuing to look all over the place. I think if I...
  2. 3dboy

    Chinese Structural Shapes

    I am designing a project to be constructed in China and I am looking for an electronic file that contains Chinese structural shapes (i.e. section properties) for use with my analysis software. I'm trying to avoid mass data entry. Can anyone point me in the right direction?
  3. 3dboy

    damping of steel stacks

    Wow! I remember the first one I did. Lots of research etc. Stacks look pretty simple but are amazing complex little pieces of work. The long and the short of the design process is to calculate the fundamental natural frequencies and modes of the stack. this is based on a dynamic analysis. I have...
  4. 3dboy

    CPU Time for many load conditions

    The single biggest factor which will affect the time your computer takes to process an FE model is going to be the amount of Ram you have. nearly every software package includes a discussion in their help files on what an appropriate amount of megs of ram per elements that you have.
  5. 3dboy

    residual stress in bent steel

    Residual stresses are present in nearly all steel shapes and are primarily the result of uneven cooling due to the hot-rolled forming process or welding. Several good sources on this are Salmon and Johnson's "Steel structures, design and behavior", "Guide to stability Design Criteria for metal...
  6. 3dboy

    Giving work to CAD operators

    Training, as has already been mentioned is key. This takes time. A good drafter can take a sketch with very little detail and knows what is going to be required and "fill in the blanks" This saves the engineer a lot of time. You can then go back after he has it pretty much done and make sure the...
  7. 3dboy

    Pre-Bent Columns

    what is a "pre-bent" column referring to? I've never heard that terminology before.
  8. 3dboy

    Concrete Arch

    You need to do a structural analysis of your set-up. you can either do it by hand or by computer analysis. once you know your moment diagram you can determine the tension face and size your rebar accordingly
  9. 3dboy

    Allowable Stresses in old timbers

    By far your most challenging task will be check the connections of the wood members. estimating a conservative value for the timbers themselves should not be too difficult, but you should do (or have done) an inspection to determine the condition of the wood. I am in the middle of a job where a...
  10. 3dboy

    High Strength Wood Diaphrams

    just for kicks and giggles you better check your aspect ratio as well. Masonry walls with a wood diaphragm have to have a rather stocky aspect ratio.
  11. 3dboy

    Lateral support for masonry walls

    If you are designing a 32'-0" high 8" masonry elevator shaft using empirical design you are not going to get it to work, nor will you be guarding the safety of the public. Also you need to check what seismic design category you are in as this brings some rather stringent detailing requirements...
  12. 3dboy

    Plain Concrete Design

    I completely and totally disagree with 24676. Concrete, while it is relatively weak in tension, does have some capacity to resist tension. The argument can be made as well that the commonly included slab on grade reinforcement used in todays construction climate (wire mesh) is totally...
  13. 3dboy

    Is there thrust in a reinforced concrete arch?

    Guys, whether something is a "curved beam" or an "arch" is determined entirely based on the boundary conditions at the supports. If both ends are restrained against longitudinal translation, you have an arch. If one end is allowed to slide you have a beam. It does not really matter which way you...
  14. 3dboy

    analysis of exterior CMU elevator tower

    Uh, you should not have any problem to get a 3 story cmu elevator shaft to support itself. I just did a 4 story one and got it to work.
  15. 3dboy

    #8 rebar equivalant to how many #4's?

    As of 1 #4 bar, .2 As of 1 #8 bar. .79 therefore 4 #4s = 1 #8

Part and Inventory Search