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Shear stress and normal stress

  1. Jun 25, 2016 #1
    1. The problem statement, all variables and given/known data
    why the shear stress is maximum at the center ? while the normal stress is maximum at the boundary ?

    ETpHIWJ.jpg
    2. Relevant equations


    3. The attempt at a solution
    why shouldn't the shear stresss maximum at the boundary ? this is because shear stress is to pull the 2 surface apart
     
  2. jcsd
  3. Jun 26, 2016 #2

    SteamKing

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    Why should shear stress be a maximum at the boundary? There is nothing being sheared there, i.e., the boundary is not being restrained.
     
  4. Jun 26, 2016 #3
    I noticed one thing , why the normal stress is maximum and minimum at the boundary?
     
  5. Jun 26, 2016 #4

    SteamKing

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    If the normal stress is produced as the result of bending, then the locations the furthest away from the neutral axis of the section will also have the highest stress, in tension and compression.
     
  6. Jun 26, 2016 #5
    can you explain further? i still dont understand
     
  7. Jun 26, 2016 #6

    SteamKing

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    Do you understand what bending stress is? How it's calculated?
     
  8. Jun 26, 2016 #7
    bending stress is shear stress?
     
  9. Jun 26, 2016 #8

    SteamKing

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    No, bending stress is not the same as shear stress.

    Bending produces normal stresses in a section, both compressive and tensile. Along the neutral axis, the bending stress is zero.
     
  10. Jun 27, 2016 #9
    why the location further away from neutral axis will have maximum stress?
     
  11. Jun 27, 2016 #10

    SteamKing

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    Because the fibers at those locations undergo the greatest stretching/compression.

    Look, instead of me spoon-feeding you elementary beam theory, it would probably be better for you to grab an elementary strength of materials text and learn this material first hand.

    http://homepages.engineering.auckla...07_Elasticity_Applications_04_Beam_Theory.pdf
     
  12. Jun 27, 2016 #11
    so , the normal stress is maximum on the the upper part of the beam , the normal stress is minimum at the lower part of the beam(expansion) ?
     
  13. Jul 5, 2016 #12
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