Experimental investigation and modelling of compressibility induced by damage in carbon black-reinforced natural rubber

Abstract

While natural rubber is commonly considered as an incompressible material, this study shows how carbon black-reinforced natural rubber (NR-CB), when subjected to various mechanical loading conditions (uniaxial, hydrostatic, monotonic, cyclic), is affected by volume change. Experiments show a volume variation even for low straining values and a significant volume change for large elongations. Moreover, volume change can be either reversible or not, depending on the loading conditions. It is related to a competition between void growth, chain orientation, and stress softening. At a microscopic scale, in situ Scanning Electron Microscopy (SEM) examinations and image analysis allow one to record damage and microscopic volume change as a function of elongation. Therefore the volume change measured at the microscopic scale is equal to the macroscopic one. Based on the experimental results, this paper shows that the hypothesis of incompressibility is worth being revisited. Thus, a nearly compressible approach was considered, where the strain energy is assumed to be the sum of spherical and deviatoric parts that are both affected by damage. The model was then implemented in a finite-element code. Good agreement was obtained between experimental results and model predictions for low triaxiality test conditions.

Effect of the Strain Rate on Damage in Filled EPDM During Single and Cyclic Loadings

“…[7]. In these conditions, the observed damage was found weakly dependent on strain rate [15]. In addition, no associated dissipative heat was expected.…”

Experimental Investigation of the Performance of SBR and RSS Materials as a Sliding Bearing Element

“…Liu et al investigated the lubricating properties of water-lubricated rubber bearings at high rotational speeds in an experimental study [7]. Cantournet et al carried out an experimental investigation and modelling of compressibility due to damage in carbon black-reinforced natural rubber [8]. Pang et al investigated the tribological properties of graphene oxide-reinforced ultra-high-molecular-weight polyethylene under seawater lubrication conditions [9].…”

Effect of the Strain Rate on Damage in Filled EPDM during Single and Cyclic Loadings

“…[ 7 ]. In these conditions, the observed damage was found weakly dependent on strain rate [ 19 ]. In addition, no associated dissipative heat was expected.…”