yield stress

A metal rod begins to permanently deform at its yield stress.

Definition

1. Noun:
   • Material science/engineering: "yield stress" refers to the amount of stress (force per unit area) that a material can withstand before it begins to deform permanently (plastically). It marks the transition from elastic deformation (where the material returns to its original shape after the load is removed) to plastic deformation (where the deformation is permanent).

Usage Examples

• Noun:
  • The yield stress of steel is much higher than that of aluminum. (The point at which steel starts to permanently deform is greater.)
  • Engineers must ensure that the applied load does not exceed the yield stress of the bridge's support beams. (They must keep stress below the limit to avoid permanent damage.)
  • When testing a new alloy, the yield stress is a key parameter measured in the tensile test. (A crucial value indicating when the material yields.)

Advanced Usage

• "Yield stress point": a specific value on a stress-strain curve where yielding begins.

  • The yield stress point is often identified by a sharp drop or plateau in the curve. (The exact location where permanent deformation starts.)

• "Yield stress in rheology": in the study of fluids (especially non-Newtonian fluids), it is the minimum stress required to make a material flow like a liquid.

  • Toothpaste has a yield stress; it does not flow until you squeeze the tube. (It behaves like a solid until a certain force is applied.)

Variants and Related Words

• Yield (verb): to give way under pressure; to produce or provide.

  • The material will yield under excessive load. (It will begin to deform permanently.)

• Yield point (noun): another term for yield stress, often used interchangeably.

  • The yield point is critical for designing safe structures. (The threshold for permanent deformation.)

• Stress (noun): force per unit area applied to a material.

  • Stress is measured in pascals (Pa) or pounds per square inch (psi). (A fundamental concept in physics and engineering.)

Synonyms

• Elastic limit: the maximum stress a material can endure without permanent deformation (closely related but not always identical to yield stress).
• Proportional limit: the stress at which stress-strain proportionality ends (often slightly below yield stress).

Related Idioms

• "To yield to pressure": to give in or submit to force (figurative use, not technical).
  • The government yielded to public pressure and changed the law. (It gave in to demands.)

Note: There are no common phrasal verbs or idioms directly associated with "yield stress" as a technical term.