Free Courses

[FAQ]

Kt is an arbitrary multiplier on the calculated FE stress. It is used to obtain the nominal stress to be used in the fatigue evaluation. The Mechanical fatigue tool uses the nodal FE stresses to assess fatigue damage. It assumes that the FE model adequately captures the peak stress, so a multiplier is not required (Kt = 1). A Kt equal to 1.0 does not mean that Neuber’s equation is always unity. However, if for example, instead of using the FE nodal stress, the fatigue tool used the linearized membrane plus bending stress along path through the thickness. That stress value would not represent the nominal peak stress. You would need to multiply it by the appropriate elastic stress concentration factor (Kt) to obtain the peak stress.