Vibration Characteristics of Tread Stocks

Abstract

Nonlinear vibration characteristics of tread compounds, as evidenced by a dependence of modulus and internal friction on amplitude, were studied in order to reach an understanding of these unexplained phenomena in terms of plausible structural alterations which may occur in the tread compounds because of vibration. This information is interesting both for a more exact description of the deformation processes in tread compounds, and because of the necessity of dealing with the effects in any dynamic testing procedure. Nonlinear vibration characteristics are readily observed for tread stocks of both Hevea and synthetic rubbers in the mechanical range of frequencies. Experiments were undertaken to study the extent to which these effects depend on temperature, compounding variables, and type of vibration. It may be shown that the nonlinearity is not due to temperature rise from vibration, although precise measurements are complicated by the temperature rise. The effects occur for stocks reinforced with fine silica pigment, Pliolite resin, and higher loadings of pigments generally considered to be nonreinforcing, as well as for those compounded with reinforcing blacks. The pigment loading necessary for the same degree of nonlinearity increases with the pigment size. The effects are observed in unvulcanized tread stocks and occur for vibrations in both shear, compression, and tension. Measurements of the nonlinearity for tread stocks over a range of temperatures suggest that the vibration elicits structural changes in the rubber analogous to those observed in the rheology of rubber solutions and raw rubber. The nature of these changes can be interpreted by the rheological criteria of structure developed for non-Newtonian systems. Such recognized mechanisms for structural viscosity as orientation, deformation, and breaking and reforming of bonds of the flow units are useful in explaining the phenomena observed. The effects appear to be of such magnitude that they should be taken into account in any exact study of the effect of modulus on tread wear and performance.

Study of the reinforcing mechanism and strain sensing in a carbon black filled elastomer

“…Payne [9] has concluded that the nonlinear behaviour of filled vulcanized elastomers is rooted in the breakdown of carbon black network structure, and the energy involved in this breakdown comes from the van der Waals forces between the carbon black particles. Similar ideas have been proposed in previous works [5,7]. Later this interpretation however, has been questioned by several researchers [10,11], given that Payne effect is also observed at low filler loadings, where the inter-aggregate distances are beyond the range of van der Waals forces.…”

Load Dependence of Dynamic Viscoelasticity of Epoxy Resin and its Composites

“…High loads often cause composites to generate modest or large deformation and exhibit nonlinearities. Many literatures have reported the load dependence of dynamic viscoelasticity about rubber and thermoplastic composites [1][2][3][4][5][6][7][8]. The increasing dynamic load causes a decrease in storage modulus and increases in loss modulus and loss tangent [1][2][3][4]8].…”

“…The increasing dynamic load causes a decrease in storage modulus and increases in loss modulus and loss tangent [1][2][3][4]8]. In contrast, the increasing static load may lead to an increase in storage modulus [2][3][4][5][6][7][8]. Among this research, the most well known is about carbon black filled rubber and the related phenomenon known named as the Payne effect.…”