Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

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

Search results for query: *

  1. bugbus

    Paradoxical strut-and-tie tests (less = more)

    I came across this paper recently which has me quite puzzled. In summary, 3 types of deep-ish beams (L/D = 4.4) were tested to failure. The first, a simply-supported rectangular beam ("Reference"); the second with an inner void formed to match the assumed strut-and-tie arrangement ("Void"); and...
  2. bugbus

    Interesting ponding/deflection problem

    @prex, I agree that unless there is a constant supply of water to fill in the gap that forms, the solution no longer works. The instant the beam sags from its initial profile, the loading from the liquid no longer reaches the ‘top’ and is no longer proportional to the deflected shape. Also...
  3. bugbus

    Interesting ponding/deflection problem

    @Craig_H thanks for the info, that’s great. I wasn’t aware of this. Agree with your last comment too.
  4. bugbus

    Interesting ponding/deflection problem

    I agree, the initial condition is a little poorly worded. Maybe a neater way of asking the question is just whether there is a stable configuration for an elastic plate where the distributed load is proportional to its deflected shape. However, disagree that any amount of liquid will cause the...
  5. bugbus

    Interesting ponding/deflection problem

    I played around with a Strand7 model for the above example, i.e., 10 mm thick steel (E = 200,000 MPa) plate filled with water (γ = 10 kN/m3). I checked a plate with less than the critical span length (L = 3.4 m), more than the critical span length (L = 3.8 m), and then the theoretical critical...
  6. bugbus

    Interesting ponding/deflection problem

    I think I have found a solution (I only say this tentatively) - the derivation is a work in progress (and may be wrong). Essentially this boils down to a 4th order ODE where (d4Δ/dx4)=(Bγ/EI)Δ(x), where Δ(x) is the deflection. The solution is in the form of a sine curve. Solving, with some...
  7. bugbus

    Interesting ponding/deflection problem

    There was a previous thread about water ponding on slabs that got me thinking about an interesting problem. I have not had any luck solving this theoretically, so for now it remains just a thought experiment. Imagine a massless plate with elastic modulus E and thickness t that is simply...
  8. bugbus

    Reinforcement Development Length

    I see your point now. I would say it is probably a matter of bar size then. It is not stated anywhere in the codes, but the requirements for fitment anchorage seem to be intended for smaller bars sizes only (up to N20 say). I had previously asked this same question to Ian Gilbert who confirmed...
  9. bugbus

    Reinforcement Development Length

    My understanding is that the longitudinal bar in the corner of a fitment improves anchorage of the fitment in two main ways: (1) it acts as a mechanical anchorage to the fitment, distributing the concentrated force at the bend over a larger area; and (2) it controls splitting in the plane of the...
  10. bugbus

    Bolt areas (Tensile stress area, Minor diameter area, Shank area)

    The largest I’ve seen was for the baseplate of a cantilever sign gantry over a road I designed, which had M42s in Grade 4.6 from memory.
  11. bugbus

    Bolt areas (Tensile stress area, Minor diameter area, Shank area)

    I made a spreadsheet for this because I found the various areas so confusing and hard to calculate Here are the areas up to M64:
  12. bugbus

    750 AUD per year for Engineer Australia membership. Is it a joke?

    I've said it before and I'll say it again - I believe EA's principle function is as a quasi immigration service for overseas engineers. That, and scalping money from membership fees. I don't actually know what it is they do to support engineering as a career in Australia, or how they advocate...
  13. bugbus

    Calculating characteristic strengths based on test data

    @sdz, thanks, I'll take a look @Euler07, thanks, these are great sources. I'll have a look and let you know.
  14. bugbus

    How to Design RC Pier under high lateral and tension load (CSA Standards)

    The interaction diagram can be extended downward to include combined tension + bending, the region between (D) and (E) in the following pic. It's just often not shown on interaction diagrams because the usual case is compression + bending. I believe that constructing a straight line between the...
  15. bugbus

    Calculating characteristic strengths based on test data

    Currently I'm working on a spreadsheet to calculate characteristic strength values based on test data (mainly concrete cylinder strength, but in theory could apply for anything). The gist of it is as follows: Calculate sample mean (x̄) Calculate sample standard deviation (s) Based on number of...
  16. bugbus

    Buckling capacity of twisted plate strut

    @Smoulder called it correctly I checked a simple example of L = 500mm, cross section of 25x10mm / 10x25mm, with number of divisions from n = 2-9. I checked a few different scenarios, depending on whether the end segments are both stiff or both flexible, or one of each. And I made sure that the...
  17. bugbus

    Buckling capacity of twisted plate strut

    Very interesting suggestions, thanks all
  18. bugbus

    Buckling capacity of twisted plate strut

    @GregLocock, will definitely look at that as an alternative approach, thanks @Smoulder, agree, it seems like the solution would end up being similar to that As far as finding a closed solution to the critical buckling load, I'm basically stuck at this point. My thinking is that the variation...
  19. bugbus

    Challenges in Modeling Live Loads for Seismically Isolated and Cable-Stayed Bridges

    Interesting, I wasn't aware about that part of AASHTO, thanks
  20. bugbus

    Buckling capacity of twisted plate strut

    OK, it turns out this could be more straightforward than I first thought :LOL: I was playing around with this in a FE software. As an assumption, I modelled the stiffer parts as fully rigid elements. I don't think that would be unreasonable, e.g., for a typical plate with aspect ratio of 5, the...

Part and Inventory Search

Back
Top