Evaluation of Static and Dynamic stiffness of rubber grommet by experimental and FEA method

Vibration control is most important in automotive applications and generally rubbers are used to dampen these vibrations due to their inherent nature and low-cost manufacturing methods. Now to select a rubber material shore hardness is considered in engineering applications, but to additionally control the behaviour we need to understand its static and dynamic stiffness. These values help to determine the vibration isolation obtained by these rubbers. In this paper, we will discuss methods to calculate the static and dynamic stiffness of rubber grommets using experimental methods and FEA modelling. As elastomers have non-linear material properties various material modelling techniques in FEA are used to capture multiple phenomena like creep, fatigue and dynamic conditions. Rubber compounding is used to improve the physical and chemical properties which in turn would give desirable linear characteristics. Certain guidelines and thumb rules are used in the rubber industry for different loading conditions to have linear stiffness behaviour. Static and dynamic stiffness values obtained by experimental and FEA modelling are in a variation of below 5%.