Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations SSS148 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. JStephen

    Theoretical Question - Planar Truss Problem

    A quick check through, I may be missing something: First, you have to assume "small deflections". Let x be the angle between force P and the spoke in question. In that case, the deflection in each spoke will be cos(x) times the deflection in the direction of the force, and the component of...
  2. JStephen

    Reinforcement congestion - How much is too much?

    I've used odd spacings before, nobody seemed to have a problem with it. On the #8 @ 6"/4", if it gets too close, you can use a double layer each way or bundled bars.
  3. JStephen

    Foundation Requirement for 40m High & 2.5m diameter stack

    Are you involved in the design of the stack itself? If so, look into vortex-shedding issues that can increase the wind loads or otherwise affect design. Also watch design temperatures, thermal effects.
  4. JStephen

    API 650 Annex S S.4.14.2 (c)

    I would interpret that wording to mean each part has to be greater than 3/4", not that the sum of the thicknesses is greater than 3/4", so I would say "no". That could be reworded more clearly.
  5. JStephen

    Water tank Manhole Design Example

    Ah, the inswing-manway. That is not covered by API-650. Per AWWA D100, the excess shell plate area and the area in the neck are included in the reinforcing. That style of manway has the neck intentionally built up to furnish full reinforcing area via the neck, without needing a reinforcing...
  6. JStephen

    Thailand/Myanmar Earthquake: VIDEO Dramatic collapse of a high rise in Bankok

    A video on this building. I haven't been paying attention to the details, so not sure if there's that much new or different:
  7. JStephen

    Basic Structural System - equipment pad

    "N/A, slab only" if you want it specifically just for the pad. For pad + equipment, maybe "Steel distributed mass cantilever structure" or "Inverted pendulum type structure" (pulling choices off Table 15.4-2 in ASCE 7-16).
  8. JStephen

    History of modular water tank construction

    An intriguing question. I had not heard of those before. In the US, watering tanks were usually wooden or riveted steel. I have just always assumed that this usage dated to the very dawn of railways as well. Googling up some of the Cornish mine engines inevitably shows the engine but not the...
  9. JStephen

    Thailand/Myanmar Earthquake: VIDEO Dramatic collapse of a high rise in Bankok

    It's not obvious that the building is moving that much in the video, until you notice those curtains/tarps alternately moving in and out.
  10. JStephen

    ANSYS - Tube Bending and Measured Ovality

    My impression- you are confusing two different effects. A tube flattens when squished between two flat plates due to applied force. I think (but can't necessarily prove) that a tube subjected to pure moment would tend to flatten as well, without any applied force. So when you wrap the tube...
  11. JStephen

    Temporary Concrete Block Anchorage

    I assume seismic loading is based on treating this as a fixed rigid object. One of the ASCE short courses I took discussed seismic loading based on a rigid object rocking. Which increases the period and might reduce seismic loading. Similarly, if the analysis allows for sliding of the...
  12. JStephen

    Rectangular Storage Tank - Thermal Movements ?

    The heat transfer to both inside and outside surfaces will be due primarily to convection. In figuring convection heat transfer, the driving factor is difference between fluid temperature out away from the surface, and the surface temperature. IE, you do not assume surface temperatures are...
  13. JStephen

    Rectangular Storage Tank - Thermal Movements ?

    On the "fully fixed at both ends"- what is it fixed to? Normally a tank bottom would be resting on sand, concrete, or pad material, but not fixed to it, either. The shell and bottom are attached to each other, but there is no mechanism to make them at substantially different temperatures. If...
  14. JStephen

    Misadventures in Rubber Stamping

    If you're in the same location, actually sitting down with them in person as opposed to emailing, etc., might help iron out some stuff. Some issues are just hard to deal with. At a past workplace, the employers (all non-engineers) viewed engineering as "putting lines on paper". So the more...
  15. JStephen

    Rectangular Storage Tank - Thermal Movements ?

    For a typical cylindrical tank operating at ambient temperature, there is zero consideration given to these effects. Which is one reason you won't find much in AWWA D10 addressing the issue. For tanks constructed of two different metals (steel tank with aluminum roof, for example), thermal...
  16. JStephen

    Required thickness according to API 620

    Use the first two equations for the cone. Check top of cone, bottom of cone, places where plate thickness changes and other intermediate points to confirm which locations control. W and F will both be negative, with loads above the section in question acting down. Pressure uplift on the roof is...
  17. JStephen

    How to accurately and quickly convert inches to millimeters in technical drawings?

    My brother once worked at a pacemaker company. Very highly regulated, medical field. The pacemakers came with a wire lead that the surgeon would trim when he installed the pacemaker. So it didn't much matter how long it was (as long as it was long enough!), but still had to be shown precisely...
  18. JStephen

    How to accurately and quickly convert inches to millimeters in technical drawings?

    If you can get the CAD files, you can fix some of this in dimension styles, etc., assuming drawings are to scale. One big decision: Are you trying to reproduce the same exact thing either way, or an equivalent item? Example: screw threads. You can get similar sizes in US and metric, but those...
  19. JStephen

    Bottom Repair of Water Fixed Roof Tank

    Usually, grind smooth for coating, not flush. Test with vacuum box or equivalent. If it's an API-650 tank, refer to API-653 for requirements.

Part and Inventory Search