Numerical studies on the self-heating phenomenon of elastomers based on finite thermoviscoelasticity

Due to their typical material characteristics, elastomer components are used in almost all areas of engineering. In many cases, these components are subject to large cyclic deformations which result in hysteresis and dissipation-induced self-heating. Further they are exposed to varying ambient temperatures. Increased component temperatures can lead to the loss of a function or to total failure. Therefore, it is important to understand the causes and influences of critical temperatures and to identify them early in the development process under the condition of efficient applicability. In addition to the calculation time and accuracy, this also includes the experimental effort required to identify the material parameters and perform validation measurements. Within this work, the phenomenon of dissipative heating in elastomers is investigated in a numerical study using a modified model of the finite thermoviscoelasticity. For this purpose, a sufficiently simple material model was formulated and implemented under the assumption of the quasi-incompressible material behaviour. Based on this, the type and the characteristic features of the self-heating effect are specifically considered, and its dependence on thermal and mechanical initial and boundary conditions is studied. Thus, a new suitable parameter is introduced, which is particularly useful to identify critical loads. Analogously, the identification of dissipation-sensitive temperature ranges is presented. The utility of the general steadystate equilibrium condition as initial condition is also shown. Furthermore, the influence of the material properties on the steadystate equilibrium is demonstrated for the first time through parameter studies. Based on these findings, recommendations for modelling, calculation and experimental parameterisation are proposed.