ABSTRACT
The experimental investigation of viscoelastic behaviour of cyclically loaded elastomeric components with respect to the time and the frequency domain is critical for industrial applications. It is known that elastomers can enter the state of structural resonance or antiresonance, thereby influencing the noise-vibration-harshness (NVH) behaviour of the entire system. Since the relevant excitation frequencies for applications with permanent magnet synchronous motor (PMSM) are substantially higher than those in case of conventional drivetrains, high-frequency dynamic stiffness measurements were performed up to 3000 Hz on a newly developed test setup for elastomeric samples and components. The new Test Bench for Dynamic Stiffness (TBDS) is compared with the standard dynamic measurement method for characterisation of soft polymers, such as Dynamic Mechanical Thermal Analysis (DMTA). A significant difference between the measured dynamic stiffness values caused by the internal resonance of the bushing is presented. Moreover, the validation of this behaviour through numerical simulations as part of the concept of virtual prototypes is equally important. The simulations of cyclically loaded specimens are carried out with the help of standard shifted complex compression modulus obtained from DMTA and the results are compared with the measurement conducted with help of TBDS. The simulations are then utilised in frequency range typical for electric vehicles (EV).
