Fatigue Test
A fatigue test tests a material's durability under repeated loading until it breaks. This is used to create S-N curves and Wöhler curves.
Physico-chemical mechanism of action
A fatigue test involves applying repeated mechanical loads to a material to test its durability. These loads can be shear, tensile, or compressive. The test continues until the material finally breaks.
Metallurgical relevance & risks in welding
Fatigue tests are crucial for the safety and lifetime of components under varying loads. A faulty test can lead to inaccurate results, which can cause incorrect predictions about component lifetime. This can lead to safety risks in service.
Workshop practice & action instructions
For fatigue tests, the following steps must be observed:
1. Material selection: Choose the right material for the test that matches the actual application.
2. Load setting: Define the type of load (e.g., shear, tensile, or compressive) as well as the amplitude and frequency of the loads.
3. Measurement and data recording: Continuously measure the strain or displacement of the specimen during the test and record these data.
4. End condition: Define when the test is terminated (e.g., at a certain degree of strain or after a certain number of cycles).
5. Evaluation: Analyze the collected data and create life and Wöhler curves to understand the material's behavior under cyclic loading.