01 Introduction and fatigue time histories

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  • Опубліковано 20 січ 2025

КОМЕНТАРІ • 5

  • @LittleGnawer
    @LittleGnawer 3 роки тому

    Nice idea with the paper clips!

  • @sphinxgiza9613
    @sphinxgiza9613 3 роки тому

    Correct me if I were wrong, but the way the axle is loaded will create tension in the top fibers at the middle of the axle, not compression. Furthermore, y in the stress equation is the radial distance measured from the neutral axis (approx. in the middle) for small deflection scenario. Thanks.

    • @mbarkey.mechanics
      @mbarkey.mechanics  3 роки тому

      I don't think there is any inconsistency between your comment and my lecture, see 21:37. The moment is negative in the middle of then (along the length of the beam/axle) and with the negative sign in sigma = -My/I there is a positive (tensile) stress at the top. y is measured from the centroid as indicated in my figure at 21:37 and 23:38 and is consistent with my time history under point 1 for a point that starts on the right at y = 0 and travels around the axle counter-clockwise .

    • @sphinxgiza9613
      @sphinxgiza9613 3 роки тому

      @@mbarkey.mechanics Thank you very much for your prompt reply. It is just when it was mentioned that the point A, see 20:21 is in compression, I was a bit alarmed :). But I believe we both agree now to the state of stress for point A (tension).
      My second comment relates to S=MY/I equation, as you know Y is the distance of the point where stress is calculated measured from the neutral axis. I see you are basically expressing Y on a vertical axis, which is fine considering the axle is axisymmetric. Thanks again for your fast reply.

  • @HRWU
    @HRWU 3 роки тому

    thx for uploading! it's just way too quiet to be heard cleaerly without using an earphone.