Temperature dependency of a viscoplastic constitutive model for rubber with reinforcing fillers
2015 (English)In: Constitutive Models for Rubber IX - Proceedings of the 9th European Conference on Constitutive Models for Rubbers, ECCMR, CRC Press/Balkema , 2015, 149-156 p.Conference paper (Refereed)Text
A material model is presented that captures the amplitude and frequency dependency of rubber with reinforcing fillers at temperatures between 23 to 85°C. It is a modification of the authors previous work and the basic principle is a smooth elastoplastic element in series with a viscoelastic network, implemented in the time domain. The rheological equivalence is based on the observation in literature that the frequency dependency of filled rubber is stronger for smaller strain amplitudes than for large amplitudes. Finally, the assumption that rubber with reinforcing fillers is thermo-rheologically simple is not always true for higher filler concentrations, resulting in discontinuous master curves for the temperature- frequency dependency. There as on for this discontinuity is that the amplitude dependency is temperature dependent. Therefore, material characterizations evaluated at a low strain amplitude could lead to erroneous results when a higher strain amplitude is of interest. Instead, it is suggested that a material model is fitted to a wide range of experimental data in order to enable realistic calculations of an actual component under operational conditions. To test the constitutive model, a double shear test specimen of natural rubber with 50 phr of carbon black filler is subjected to sinusoidal strains. The amplitudes are varied between 0.2 and 50% shear strain for frequencies between 0.5 and 20 Hz at 23, 60 and 85°C. The derived model needs only 5 material parameters to be fitted to experimental data and captures the storage and loss modulus for the entire range of strain amplitudes and frequencies, as well as non-sinusoidal loading conditions. Moreover, with the proposed modelling technique, it is expected that frequencies well above the available experimental data can be simulated. This is important, since the purpose of every model should be to make predictions outside of the range of available experimental data.
Place, publisher, year, edition, pages
CRC Press/Balkema , 2015. 149-156 p.
Carbon, Carbon black, Characterization, Constitutive models, Digital storage, Reinforcement, Rubber, Shear strain, Strain, Time domain analysis, Carbon black fillers, Frequency dependencies, Material characterizations, Operational conditions, Storage and loss modulus, Temperature dependencies, Temperature dependent, Viscoplastic constitutive modeling, Fillers
IdentifiersURN: urn:nbn:se:kth:diva-187538ScopusID: 2-s2.0-84959513528ISBN: 9781138028739OAI: oai:DiVA.org:kth-187538DiVA: diva2:937997
9th European Conference on Constitutive Models for Rubbers, ECCMR 2015, 1 September 2015 through 4 September 2015
QC 201606162016-06-162016-05-252016-06-16Bibliographically approved