Some observations on the numerical solution of the Ottosen-Stenström-Ristinmaa high-cycle fatigue model

Abstract

Some years ago, Ottosen, Stenström and Ristinmaa introduced a high-cycle fatigue model based on the continuum approach. The model is formulated as a fully implicit differential equation and an ordinary differential equation.  The corresponding numerical solutions are compared. We demonstrate pitfalls in the process so that appliers are able to avoid these problems. Especially,
we show that the results depend on the initial value of the evolution equation. We propose a method to choose such an initial value that the estimated Wöhler curve fits the measured data.