Simulating Very Large Tire Deformations with CDTire

The full vehicle simulation on durability proving grounds is a well established technique in the development process of passenger car manufacturers. The respective road surfaces are designed to generate representative spindle loads and typically include events that will result in large tire deformations. Depending on manufacturer and the combination of vehicle size and wheel properties, these deformations can be so large that the tire belt and/or sidewall have contact with the rim crown (protected by the tire sidewall). The current tendency to low-aspect ratio tires reduces the available deformation capability of the tire while simultaneously introducing larger nonlinearities in the sidewall behavior.

After a short overview of the standard modeling technique used by the CDTire model family to handle such events, a refinement of this technique is introduced, modeling both the non-linearity behavior of the sidewall and a possible subsequent rim contact. This refinement also takes the rim deformation into account. The parameter identification procedure for the large deformation extension is explained and validation results are shown. In combination with extended postprocessing functionality, this model extension enables CDTire in misuse-like simulations.