Force Method, Indeterminate Frames, Example - Structural Engineering

Поделиться
HTML-код
  • Опубликовано: 3 ноя 2024

Комментарии • 8

  • @rosinahfilms9809
    @rosinahfilms9809 6 месяцев назад

    Is it possible to determine the surface bending stresses next to the reactions due to the external loads. given the cross-section of beam is known.

    • @drofeng
      @drofeng  6 месяцев назад +1

      Yes but the bending stress should be zero at the pins as the bending moment is zero there. Compression and shear will be the prominent design loads at the reactions

    • @rosinahfilms9809
      @rosinahfilms9809 6 месяцев назад

      @@drofeng Thanks for the for that, but what happens if both legs are fixed (no pin connection). I'm trying to determine the maximum bending stress due to that external load. lets assume the beam has cross section of a rectangle.

    • @drofeng
      @drofeng  6 месяцев назад

      Doesn’t matter if it’s fixed, the peak bending stress will just be at a different point in the column. For the pinned case for example, you take the Mac bending moment in the column from the bending moment diagram, then use My/I to get the bending stress. If the section is rectangular, with the depth d being parallel to the applied lateral load, y=d/2 and I=bd^3/12
      For the beam, same concept.

  • @zebmcleod3361
    @zebmcleod3361 7 месяцев назад

    I have an almost identical problem for a uni assessment the only difference is the force from the left is a 3rd of the way up the column. I've used your method and it isn't consistent with results beamguru the online software. Is the because my force is in a slightly different location? also the reaction force from the left support is going down as I'd assume it's being pulled from the force pushing the frame to the right.

    • @drofeng
      @drofeng  7 месяцев назад

      For the top case (applied external loads), the following will be different:
      * Vertical reaction at the roller (retake moments about the pin with the new load applied one third up the column)
      * Bending moment diagram on the left column will be piecewise linear
      Then you need to segment the left column in two parts, to get the volume between the real and virtual BMDs
      You can email me your attempt if you like and I can have a look:
      drofeng@gmail.com

  • @HashemAljifri515
    @HashemAljifri515 3 месяца назад +1

    You didn't explain how the sections are taken for the moment equation.. I won't memorize the formula for the deflection for each structure!

    • @drofeng
      @drofeng  3 месяца назад

      You don’t have to remember the deflections. With frames, we typically make simple analogies to quickly draw linear bending moment diagrams, as using bending moment equations for each member becomes time consuming
      It’s really the same process as coming up with the shear force and bending moment equations for beams, with the sign convention explained in the following video for frames
      ruclips.net/video/VSzi2eBsMeA/видео.htmlsi=19RWW3zGoJBzXOel