• Question: What is a Mohr's circle graph

    Asked by Dr Stookniey to Sheryl on 6 Mar 2017.
    • Photo: Sheryl Williams

      Sheryl Williams answered on 6 Mar 2017:

      Hello Sefan,

      Wow , this is a serious question to get me started on I’m an Engineer!!!
      So I must admit I have never heard or come across the Mohr circle graph or if I did I have forgotten all about it. So I had to look it up on Google 🙂
      It a graph used to analyse the stress on a material, drawing the Mohr circle helps you to determine the principal stresses, the shear stress and to help identify/draw the stress elements.
      It seems really complicated but if you break down the steps and approach it in a systematic way you can get a grip of it.

      Sheryl

Comments

  • Photo: Andres

    Andres commented on :

    Hi Sefan,

    Even Sheryl wasn’t really sure about what Mohr Circle was, his explanation is very accurate!

    I could probably add a bit more to his explanation, from a structures engineer perspective:

    When a structure is loaded (i.e. forces or pressure is applied), the material gets stressed. However, very often you don’t just have a single load, you may be stretching the structure in different directions. Because of this, the maximum stress in the structure (stress = force divided by cross-sectional area) may not occur in the direction of the forces, but it an angled direction.

    Mohr’s circle is a graphic way to come up with this maximum stress direction (i.e. the principal stresses and maximum shear). Ideally, we would like our structure to be reinforced at this direction of maximum stress, so it is less likely to break.

    But, as Sheryl said, this is a bit more complicated than what you would learn in school, so don’t worry too much about it if you don’t understand it at the moment.

    Andres

  • Photo: 465amph45

    465amph45 commented on :

    :):)