Ansys Workbench Fatigue Module

Non-Zero Mean Stress in a Fatigue Analysis

---

This tips & tricks article illustrates how to take into account a non-zero mean stress in an Mechanical Workbench fatigue analysis.

Download: Ansys Workbench Fatigue Model (*.wbpz)

Combine static and varying load in WB Fatigue Module

ANSYS WB Fatigue Module is able to solve Constant Amplitude, Non-Proportional Loading

First here are some definitions:

Non zero mean stress loading

To create this fatigue analysis solution we have to obtain the stress result for Smaximum and Sminimum

Alternating bending stress R < -1

For instance we have an alternating bending stress with a mean compression stress.

Smaximum and Sminimum

In Ansys Workbench we have to combine the static and alternating stress in 2 static structural solutions that will give us the Smaximum and Sminimum.

Solution Combination

Once the maximum and minimum result is obtained we will be able to combine them into a Solution combination to allow the fatigue module calculate it.

Mechanical Workbench Module | Fatigue Analysis Result

In the Gerber mean stress correction theory, the compression mean stress has a penalizing impact on the fatigue life of the part.