What is yield strength?

Yield strength is an indication of the maximum stress that can be developed in a material without causing plastic deformation
.

It is the stress at which the material exhibits deformation and is a practical approximation of the elastic limit
.

In engineering structural design, yield strength is very important
.

For example, when a component is designed, it must support the forces generated during use and the component must not deform plastically
.

In other words, the material should be selected with sufficient yield strength
.

Since it represents the upper limit of the force that can be applied without causing deformation, yield strength is often used to calculate the maximum allowable load in mechanical parts
.

Various yield criteria have been established for various materials
.

However, when the material is stressed, it deforms in a way that it can recover
.

The yield strength of a material is the stress, which becomes plastic when deformed
.

Any deformation caused by a stress greater than the yield strength is irreversible
.

Due to the linearity of elastic deformation, the yield strength is also referred to as the maximum stress that can be achieved without deviation
.

Stress and strain are proportional
.

After this point a wide deformation can be observed with little increase in the applied load
.

Yield strength is expressed in N/m2 or Pascals
.

When designing components, it is important to know the yield strength of a material because it often represents the upper limit of the load that can be applied
.

Yield strength is important for controlling production techniques for many materials, such as forging, rolling or pressing
.

Tensile tests are used to evaluate the yield strength of materials
.

The test results are plotted on a stress-strain curve
.

The yield strength of a material is the stress at which the stress-strain curve deviates from proportionality
.

In design applications, yield strength is often used as an upper limit on the allowable stress that can be applied to a material
.

This is especially important in material applications where precise dimensional tolerances are required under high stresses and loads
.

By varying the dislocation density, impurity level, and grain size (in crystalline materials), the yield strength of the material can be fine-tuned
.

For materials without a well-defined yield point, yield strength is usually expressed as the stress that produces a deformation of 0.
2% of the original size, called the 0.
2% yield stress
.

The value of yield strength is important in the construction of a structure so that it can function in the elastic region under normal operating conditions
.

However, when faced with unexpected shock loads (such as explosions, fires or natural disasters such as earthquakes), the plastic area of ​​the material becomes critical, because in this case most of the energy absorbed by the material is mainly in the plastic area Contribute
.

Therefore, having higher toughness means the material can withstand this unforeseen load for a longer period of time, allowing more time for safety measures to be implemented
.

In general, yield strength increases with strain rate and decreases with temperature
.

When the latter is not the case, the material is said to exhibit yield strength anomalies that are typical of superalloys and lead to their use in applications requiring high strength at elevated temperatures
.

Yield strength anomalies are also known as "yield stress anomalies"
.

It is often difficult to determine the exact point at which yielding begins, which is why proof stress is used in practice
.

This is where the stress is considered to produce a certain amount of strain, which is used to define the yield strength
.