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Converters & Calculators
Yield Strength: Basics And Examples
What is Yield Strength?
Yield strength is a fundamental property of materials. It indicates the maximum stress that can be applied before the material undergoes permanent deformation. It is important in engineering and material science for designing structures that withstand applied forces without failing.
Relationship between Yield Strength and Tensile Strength
Yield strength marks the beginning of plastic deformation. Tensile strength refers to the maximum stress a material can tolerate when stretched before breaking. Knowledge of both properties is essential for selecting materials for various applications.
Factors Affecting Yield Strength
Several factors influence a material’s yield strength, including:
Material Composition
A material’s elemental composition significantly influences its yield strength. Alloying elements can increase strength by hindering dislocation movement within the material’s crystal structure.
Temperature
Temperature variations affect yield strength. In general, yield strength decreases with rising temperature, thereby increasing the likelihood of deformation under load.
Manufacturing Process
Processes such as heat treatment, forging and rolling alter the microstructure of a material, thereby affecting its yield strength.
Measurement of Yield Strength
Yield strength is typically measured with a tensile test. A specimen is subjected to an increasing tensile force until plastic deformation is observed, and the corresponding stress is recorded as the yield strength.
A stress–strain curve is used to determine the yield strength. The yield point is identified where the curve transitions from elastic to plastic behaviour.
Applications of Yield Strength
Yield strength is important in several applications, including:
- Construction: Ensuring that buildings and bridges carry loads without permanent deformation.
- Automotive Engineering: Designing vehicle components that can withstand operational stresses.
- Aerospace: Developing aircraft parts that remain stable under severe conditions.
Comparison Table for Common Materials
|
Material |
Yield Strength (MPa) |
Tensile Strength (MPa) |
|
Steel |
250–550 |
400–800 |
|
100–400 |
200–500 |
|
|
800–1100 |
900–1400 |
|
|
Copper |
70–200 |
200–400 |
|
Brass |
150–350 |
300–600 |
Additional information is available at Stanford Advanced Materials (SAM).
Frequently Asked Questions
What is the difference between yield strength and tensile strength?
Yield strength is the stress at which a material begins to undergo permanent deformation, whereas tensile strength is the maximum stress a material can withstand before it fractures.
Why is yield strength important in engineering?
Yield strength ensures that structures and components sustain applied loads without permanent deformation, thereby maintaining safety and reliability.
How is yield strength measured?
Yield strength is measured using a tensile test. A specimen is extended until plastic deformation is observed, and the corresponding stress is recorded.
Can the yield strength of materials be increased?
Yes, yield strength can be increased through alloying, heat treatment and cold working, which improve the material’s microstructure.
Does temperature affect yield strength?
Yes, with increasing temperature the yield strength of a material generally decreases, causing it to deform under load more easily.
Chin Trento
