GUEST’s or TRESCA’s THEORY

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MAXIMUM SHEAR STRESS THEORY (GUEST’s or TRESCA’s THEORY)


                 According to this theory, the elastic failure occurs when the greatest shear stress reaches a value equal to the shear stress at elastic limit in a simple tension test. This theory is considered for ductile materials, since shearing doesn’t occur in brittle materials.
(½)(σ1 – σ3) = (½)σe           or
                                                              σ1 – σ3    =      σe

                  The maximum shear stress theory is also known as Guest’s or Tresca’s theory.

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