Defining a Fatigue Check Plot

After you run the static study, you define a Fatigue Check plot to identify regions of the model that can possibly fail due to repeated loading and unloading.

  1. Right-click Results and click Define Fatigue Check Plot.
  2. In the PropertyManager, under Modifying Factors:
    • Click On/Off Loading .
      This option applies zero-based loading to determine the mean and alternating stress.
    • In Surface Finish Factor, select Machined.
      A surface finish correction allows the estimate of the fatigue strength of the part in its working condition.
    • In Loading Factor, select Axial.
      Fatigue limits are usually determined from test specimens under bending. A specimen loaded in tension has a lower fatigue limit.
    • For Size Factor, type 0.80.
      Based on experimental results, larger parts have lower fatigue limits than smaller parts. The range is from 0.1 to 1.
    Simulation considers the material's fatigue strength as half the material's tensile strength. The cumulative factor is equal to the product of the three reduction factors and reduces the material's fatigue strength by 0.686.

    Simulation runs the fatigue check plot calculations. A yellow icon indicates that parts of the model could fail due to cycling loading.

    Blue regions indicate that the stress levels are so low that fatigue should not be a concern with the specified loading. Red regions indicate that the specified loading will consume a percentage of the assembly's life. Red regions cover a very small area of the parts.

  3. To increase the minimum acceptable factor of safety for the material's fatigue strength, for Minimum safety factor type 1.50 and press Enter.
    Simulation divides the fatigue strength by the given factor and updates the color of the parts in the graphics area. Notice that the red regions slightly expand because the fatigue strength is reduced.
    To increase the material's fatigue strength (equals half the material's tensile strength), for Scale this value, enter a value greater than 1. The red regions contract.
  4. Click .