Yield and Ultimate strength

Definition of Yield strength:

            The yield strength or yield point of a material is defined as the stress at which a material begins to deform plastically. Prior to the yield point the material will deform elastically and will return to its original shape when the applied load is removed.

Importance:

Knowledge of yield point is vital when designing a component since it generally represents an upper limit of the load that can be applied.

Formula :

              Yield strength= yield load/area

Definition of Ultimate strength:

            Ultimate strength is the maximum stress that a material can withstand without failure or rapture. It is given by:

                               Ultimate strength = ultimate load/Area