Improvement of predictive testing with respect to crack propagation and wear of tyre treads

• Applicants: Professor Dr. Gert Heinrich; Professor Dr. Manfred Klüppel
• Subject Area: Polymer Materials ; Preparatory and Physical Chemistry of Polymers
• Term: from 2013 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 236399313

Based on theoretical and experimental results under cyclic loading, new testing concepts were designed within the DFG Research Unit 597 Fracture Mechanics and Statistical Mechanics of Reinforced Elastomer Blends. The objective of the proposed project is to develop improved concepts of predictive testing with respect to crack propagation that are closer to the real operating conditions of tyre parts. Together with industrial partners these new concepts will be validated and optimised methodically with regard to specific applications, i.e. especially the chip and cut problem at abrasive operating conditions in case of off-road truck tyres. By means of dielectric spectroscopy on truck tyre tread samples it should be clarified if flow and relaxation processes during vulcanisation lead to a pronounced anisotropy of the carbon black network and to which extend modifications of carbon black network under persistent loading favour the chip and cut phenomenon.An improved dynamic testing method developed within FOR 597 using simultaneously pre-notched tensile and pure shear specimens will be transferred to industrial application. The fracture processes and the specific development of the crack front as well as the physical properties in the vicinity of the crack front will be investigated by a new optical online-analysis.Experimental investigations with the Tear Fatigue Analyser will be supported by the finite element analysis of stress softening and calculations of the tearing energy at various loading conditions.

• DFG Programme: Research Grants (Transfer Project)
• Participating Institution: Continental Reifen Deutschland GmbH