Rubber characterization for tire modeling

Since tire rubber exhibits a complex history and temperature dependent mechanical response, a thorough virtual analysis of tires necessitates the use of non-linear viscoelastic material models in conjunction with numerical techniques like FEA. An important undertaking in running these analyses is the development of an experimental program to generate reliable data for calibrating such material models. Two important aspects of rubber behavior that should be considered while developing such a program are presented here: (1) a mean/static strain effect on dynamic properties and (2) Payne effect and its recovery with time during thermo-mechanical testing. Simple corrections are proposed to account for errors introduced in the measured (apparent) dynamic mechanical properties due to these effects. Accounting for these errors is expected to yield true material data for material model calibration.