Yield Stress is best described as

Yield Stress is best described as

• A. Noticeable deformation in the part leading to high stress concentration at yield point
• B. It is the maximum load the part can carry
• C. It is the linear portion of the stress-strain curve
• D. It is the stress coordinate value at the highest point on the curve

Answer: (A)

Yield stress is the stress level at which a material begins to deform plastically—the onset of permanent, non-recoverable deformation. Up to this point the material behaves elastically, so if you remove the load it returns to its original shape. Once you pass yield, plastic flow begins and some deformation remains, which is why this point is described as where noticeable deformation starts. In practice, designers often use the 0.2% offset yield strength to define this stress when a sharp yield point isn’t clear. It isn’t the maximum load the part can carry (that’s the ultimate strength), nor the linear elastic portion, nor the highest point on the curve.

Yield stress is the stress level at which a material begins to deform plastically—the onset of permanent, non-recoverable deformation. Up to this point the material behaves elastically, so if you remove the load it returns to its original shape. Once you pass yield, plastic flow begins and some deformation remains, which is why this point is described as where noticeable deformation starts. In practice, designers often use the 0.2% offset yield strength to define this stress when a sharp yield point isn’t clear. It isn’t the maximum load the part can carry (that’s the ultimate strength), nor the linear elastic portion, nor the highest point on the curve.