Stress Transformation

When you select a general log-linear (GLL) or cumulative damage (CD) model, you must use the Stress Transformation window to choose one transformation for each stress that is selected to be used in the analysis. To access this window, click Stress Transformation immediately above the Analysis Settings area of the control panel.

The Transformation drop-down list provides the following three options for how the stress will be transformed within the model.

Use the None X=V transformation for stress types associated with the exponential life-stress relationship (LSR). This transformation is commonly used for indicator variables (e.g., 0 = on/off and 1 = continuous operation).
Use the Reciprocal X=1/V transformation for stress types associated with the Arrhenius LSR. This transformation is commonly used for thermal stresses.
Use the Logarithmic X=ln[V] transformation for stress types associated with the inverse power law LSR. This transformation is commonly used for non-thermal stresses.