School of Engineering and Materials Science Publication:
"The creep and recovery of filled and unfilled elastomers"
Journal: Constitutive Models for Rubber II. Edited by D. Besdo, R.H. Schuster, J. Ihlemann. pp. 173-178.
The creep and recovery behaviour of both unfilled and carbon black filled NR vulcanizates were investigated at moderate stresses in tension. The aim of this investigation being to understand and examine the time dependent mechanisms that are present in both un-filled and filled elastomers subjected to a strain. A method based upon the Boltzmann superposition principle was used to compare the creep compliance with a measurement of its recovery after release from a range of constant loads held for different times. The creep behaviour was seen to exhibit the usual linear dependence on the logarithm of time for both the filled and the unfilled material. The recovery data was also seen to reduce onto a single recovery curve for any given applied tensile stress for a range of loading times using the Boltzmann superposition principle. The differences between the relative rates of the creep and the recovery behaviour can be partially attributed to the non-linearity in the stress strain behaviour exhibited in tension for the unfilled materials. For the filled materials the behaviour was more non-linear as other complications arise.
Related site: http://www.materials.qmul.ac.uk/rubber