ABSTRACT
This chapter presents an experimental investigation of the volume change of a natural rubber material under various loading conditions, both from a macroscopic and a microscopic point of view. It presents a damage-induced compressibility model; and compares the finite element calculations using this model to the experimental results. While natural rubber is commonly considered as an incompressible material, how carbon black reinforced natural rubber, when subjected to various mechanical loading conditions, is affected by volume change. Constitutive models commonly used to describe the behavior of carbon black filled natural rubber use an incompressible constraint assumption. The material of interest is a cis-1, 4-polyisoprene reinforced by carbon black and is commonly used for bearings subjected to fatigue. The modelling approach was validated by comparing the model prediction to experimental results for the other loading conditions experimentally investigated. The seven model parameters are fitted to the experimental stabilised material response under uniaxial tension in terms of stress-strain and volume-strain curves.
