Use the Strain-Based node to define the fatigue model selection and parameters for strain-based fatigue evaluation. The Strain-Based feature can be applied to domains, boundaries, edges, or points.

See Common Physics Interface and Feature Settings and Nodes for information about the Model Input.

From the Physics interface list select the physics interface where the load cycle is simulated.

If you select a Shell interface, also select a Through-thickness location — From shell interface, Top, or Bottom. This determines from which position in the shell stresses or strains are taken for fatigue evaluation. When you select From shell interface, the local z-coordinate given in the Default Through-thickness Result Location section in the settings for the Shell interface is used.

Select a Criterion — Smith-Watson-Topper (SWT), Wang-Brown, or Fatemi-Socie. This specifies the fatigue model to be evaluated. See Smith-Watson-Topper (SWT) Model, Wang-Brown Model, and Fatemi-Socie Model for details about these models. Also see Elastic Notch Approximation.

Select a Solution type — Full elastoplastic solution or Elastic solution with notch assumption. This defines how the load cycle is processed.

If Wang-Brown model is selected, also specify Mean stress correction — None or Morrow, which controls how the effect of the mean stress should be evaluated.

There are several sets of fatigue model parameters, which depend on the selected criterion and options. The combinations are listed in Table 3-1 and Table 3-2. As a default, the parameters take values From material. For User defined enter other values or expressions in the fields as needed.

If the Criterion selected is Fatemi-Socie, specify how the fatigue model parameters are provided. Select from the Shear fatigue data list — Implied from tensile data or Explicitly given. For Explicitly given enter the actual torsional data.