Dynamic characterisation of silicone rubber for human vibration representation

Dynamic responses of scaled rigid mass-silicone rubber single-degree-of-freedom (SDOF) analogue representing excitation-subject interface of the whole-body vibration (WBV) are presented for the first time. Homemade cylindrical silicone rubber specimens were constructed to represent the soft tissue at the interface. The sprung mass was 2.5 kg with a flat and a hip-borne indentation interface with the tissue. With the band-limited random base excitation, a dominant single resonance was observed for the rigid mass-silicone rubber system and also in most WBV studies. Although the frequency range at which the resonance occurred were different: 20 to 33 Hz for the current study and below 10 Hz for WBV studies, the mode of sprung mass might be similar in both scenarios. The effect of thickness and sprung mass contact contour on resonance frequency and stiffness is found to be significant. However the absence of change in the resonance frequency with different magnitudes of base excitation seems to suggest the magnitude dependent resonance behaviour of the human body is missing in the SDOF rigid mass-silicone rubber system.