Fatigue test
Under the cyclic load fatigue of materialsIn fatigue test, material fatigue by one who has a corresponding test frequency of cyclic loading to induce.This may involve pulsation of tensile or compressive load test, as well as to the cyclic loading test of tensile and compression components.
The material in the fatigue test failure usually occurs in the case of is far lower than the static ultimate strength.
Fatigue test results usually in the form of stress and load cycle diagram.Here to draw the sample split cycle number of cyclic stress amplitude variation.
Fatigue test on the one hand is used to measure feature values, on the other hand is used to measure the fatigue life.
Material fatigue
Material fatigue refers to the material or component part (s) under the effect of time-varying, repeated stress damage or failure.
Material fatigue is caused by plastic deformation, its smallest form is called the micro plastic deformation.Damage grows with the ongoing stress (crack propagation), leads to the failure of materials or components cannot be changed.
Many damage investigation concluded the following results:
- Use for a period of time without any problems components may suddenly failure.
- Failure is not caused by a single overload.
- Failure occurs in the case of is far lower than the static ultimate strength.
- Load change with time, and are often repeated.
Cyclic stress component fatigue life is limited.Before the implementation of the key components testing, therefore, should carry on the fatigue life evaluation and fatigue life calculation or fatigue test, to provide the component durability evaluation (durability).
