Advances in Understanding Thermal Effects in Rubber

In the case of an ideal rubber, one often thinks of the linear dependence of the shear modulus on temperature as an expression of the typical entropy elasticity. However, temperature dependencies of typical technical rubber materials are known to be much more complicated. This has consequences for the practical behaviour of rubber-elastic components. One well-known instance of this is the dramatic Challenger disaster. The rubber used to seal the solid rocket booster joints with O-rings did not expand at temperatures of 0 °C or below, resulting in an opening in the solid rocket booster joint through which gas attempted to escape.

The main physical reason for the heat generation processes is the hysteresis of rubber materials due to deformation and viscoelasticity. Most elastomers therefore change significantly over time when exposed to heat (and likewise light or oxygen (ozone)). These changes can have a dramatic effect on the life and properties of the elastomers. Heat development in a rubber occurs when it is subjected to a variety of compressive stresses in service. Heat evolution tests are commonly performed to estimate the quality of use and expected service life of various compounds or material options for end-product applications. New developments in recent years on test methods in this direction constitute an important part of the book. At the same time, corresponding simulation and modelling methods have been developed that contribute to a better understanding and enable the predictive simulation of self-heating and the kinetics of temperature fields in complex cyclically loaded rubber components. Specifically, finite-strain thermal viscoelastic damage models for predicting the cyclic thermomechanical response of rubber specimens under fatigue are also presented, and analytical models for heat diffusion in stressed rubbers.

Includes numerical and physical simulation Introduces thermal effects of rubber Presents experimental investigations of rubber self-heating

Auteur

Prof. Gert Heinrich

Gert Heinrich completed his physics studies in quantum physics at the University of Jena (G) in 1973. At the University of Technology (TH) Leuna-Merseburg he received his doctorate in 1978 on the physics of polymer networks and his habilitation in 1986 on the theory of polymer networks and topological constraints. In 1990, he obtained a position at the tire manufacturer Continental in Hannover (D) as Senior Research Scientist and Head of Materials Research. Heinrich continued his academic work as a lecturer at the Universities of Hannover (D) and Halle/Wittenberg (D). In 2002, he was appointed Full Professor of "Polymer Materials and Rubber Technology" at the TUD Dresden University of Technology, Dresden (D) and Director of the Institute of Polymer Materials at the Leibniz Institute of Polymer Research Dresden e. V. (IPF). Heinrich has been a senior professor since 2017. His work has been recognized by several awards, e.g. the George Stafford Whitby Award for outstanding teaching and research from the Rubber Division of the ACS, the Colwyn Medal in the UK for outstanding achievements in the rubber industry, the Carl-Dietrich Harries Medal from the German Rubber Society, the H.F. Mark Medal of Austrian Research Institute for Chemistry and Technology and the Lifetime Achievement Award from Tire Technology International Magazine.

Reinhold Kipscholl

Reinhold Kipscholl graduated as Dipl.-Ing. in engineering of data processing and electronics. He is active since more than 20 years in leading industrial positions, especially in the field of testing and characterization of materials with respect of their physical behavior. Since 20 years he was General Manager of Coesfeld GmbH & Co. KG (Dortmund), a German Company developing and producing material testing equipment for plastics and elastomers. Since 2012 R. Kipscholl is founder of PRL Polymer Research Lab (PRL), Zlín, Czech Republic researching and developing new testing methods for characterization of fracture and wear behavior of rubbers. He has been awarded with the 2018 Fernley H. Bunbury Award (Rubber Division, American Chemical Society).

Prof. Jean-Benoît LE CAM

Jean-Benoît Le Cam received the M.Eng. degree in mechanical engineering from Conservatoire National des Arts et Métiers, Orléans, France, in 2002, the M.S. degree in applied mechanics from Ecole Centrale de Nantes, France, in 2002, and the Ph.D. degree in mechanical engineering from Ecole Centrale de Nantes and University of Nantes, France, in 2005. From 2006 to 2011, he was an Assistant Professor at the French Institute of Advanced Mechanics (IFMA), Aubière, France, where he worked on mechanics of elastomers. In 2010, he received his habilitation on thermomechanical characterization of elastomers and was appointed director of the Structures and Mechanics of Materials department at IFMA. Since 2011, he is a Professor at Institute of Physics Rennes, University of Rennes (UR), France, where he is the leader of the Quantitative Imaging in Mechanics of Materials Group. From 2015 to 2020, Prof. Jean-Benoît Le Cam held the Cooper Standard Chair in mechanics of elastomers at UR and managed the Research Laboratory (LC-DRIME) in Imaging, Mechanics and Elastomers, common to Cooper Standard, UR and the National Center for Scientific Research. Since 2021, he manages the Research Laboratory (ELAST-D3) for the development, the durability and the dynamic properties of elastomers, common to Continental, UR and the National Center for Scientific Research."

Assoc. Prof. Radek Stöek

Radek Stöek obtained his diploma degree as engineer in 2005 from the Czech Technical University in Prague and received his Ph.D. in engineering science in 2012 from the Technical University Chemnitz (Germany), working with M. Gehde and parallel with G. Heinrich at IPF Dresden (G). Then he started an industrial career at Polymer Research Lab (PRL), Zlín, Czech Republic, and parallel an independent academic career at the Tomas Bata University (TBU) in Zlin. He finished his Habilitation in 2019. Currently he is holding the two positions as General manager at PRL and Head of the Rubber Department at TBU. His research and scientific interests are focused on characterization of rubber material properties with respect to fatigue and fracture mechanics and on the development of new and advanced testing methodologies, hardware and equipments. One main goal is to optimize industrial rubber products in terms of performance and durability as well as to fasten development cycles and minimizing extensive real rubber product tests before production. His work has been recognized with awards from The Tire Society (USA) as well as receiving the prestigious Sparks-Thomas Award from the Rubber Division, ACS in the USA. R. Stöek is co-author of more than 65 publications and holds six utility models.

Contenu

Temperature effects of rubbers: a microscopical perspective.- Effects of temperature on uniaxial and multiaxial fatigue of natural rubber under relaxing and non-relaxing loadings.- Identification of the part of the hysteresis that is converted into heat.- Emissivity vs. rubber composition.- Heat development during Cut &Chip mechanism.- Heat build-up - numerical prediction.- Thermo-mechanical behavior of tread rubber during high-speed friction.- Influence of thermal ageing on HBU

Heat during biaxial loading.- Dynamic viscoelasticity and hysteresis heating of filled rubber under cyclic deformation.- Including temperature effects in the theory and simulation of problems in rubber reinforcement.- Deformation-induced temperature changes in SBR and NR elastomers.- Modeling and characterization of heat transfer in interactive elastomer composites.- A review of thermal effects on elastomer durability.