Finite Element and Mesh-Free Simulation Environment for the Molding and Vulcanization of Rubber in Industrial Tire Production

• Applicant: Professor Dr.-Ing. Michael Kaliske
• Subject Area: Applied Mechanics, Statics and Dynamics
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 491401006

In the last years (2018-2021), intensive fundamental research on the numerical representation of the molding and the vulcanization process of axisymmetric, automotive tires has been carried out in the research project SENSE. Within this project, a thermo-mechanical tire molding simulation environment by the finite element method (FEM) focusing on the simulation of the process from the uncured to the final cured axisymmetric tire has been developed by the applicant Prof. Michael Kaliske at the Institute for Structural Analysis (ISD). The finite element (FE) based simulation approach uses an Arbitrary Lagrangian Eulerian (ALE) description to track the material points during the molding of the green tire to obtain a representation of the molding process (avoidance of mesh distortion). Furthermore, several advanced thermo-mechanically coupled material models have been developed to describe rubber in its cured and uncured state. However, the molding of arbitrary tread patterns is still challenging due to the complex geometry, friction and the material flow of the uncured rubber during the molding process (questions with respect to numerical stability and robustness for realistic 3D tire designs). These open research questions shall be further development steps of this transfer project between ISD and the industrial project partner Continental Reifen Deutschland GmbH. The transfer project aims to combine the strengths of fundamental academic research and innovative realization procedures of new products in a changing industrial environment subjected to digitalization of the whole process chain. Hence, the transfer project will not only bring to industrial application the simulation environment developed within the project SENSE (material model for unvulcanized and vulcanized rubber, ALE approach for rubber molding, exchange on industrial expertise) but will further contribute to the development of numerical methods for the advanced numerical description and representation of tires with arbitrary tread patterns from their manufacturing state to their service state by an alternative numerical method, the material point method (MPM). Additional new research aspects of the transfer project address the development and application of the implicit MPM as a mesh-free method for the molding of tires with arbitrary tread pattern (MPM simulation for tread) in 3D, the formulation of the MPM in the framework of thermo-mechanics, a coupling of FE methods (tire main body) with the MPM (tire tread) for the analysis during the forming and vulcanization process (manufacturing stage), and a strategy to propose an implementation of the material behavior for FEM, MPM or ALE including the description of the current material state (inelastic, nonlinear). The main objective is the development of a robust and numerically stable simulation environment for the molding and vulcanization of tires with 3D tread patterns.

• DFG Programme: Research Grants (Transfer Project)
• Application Partner: Continental Reifen Deutschland GmbH