A novel local ellipse method for ellipse-based tangential contact model applied to wheel-rail contact

In order to simplify wheel-rail rolling contact for engineering computation, it usually applies an ellipse-based tangential contact model to non-elliptical contact patch. This paper proposes a novel local ellipse method to reach this transition due to contact stiffness difference in elliptic and non-elliptical contact. The method is similar to STRIPES that regards the contact patch as some strips along the rolling direction and locating at the center of their respective virtual ellipses. However, it provides an alternative way for the determination of the local virtual ellipse using elliptic integral, normal contact pressure and longitudinal contact boundary. One novel aspect is the lateral curvature at each strip is solely determined and needs no additional modification. This method is combined with FaStrip and evaluated by CONTACT. It thus provides an efficient pre-process of simplified tangential contact model to be applied to non-elliptical contact in vehicle-track dynamics modelling and wheel-rail damage prediction.