Validation of a 3D visco-hyper-elastic finite element model for a pre-stressed vibrated distal forefinger phalanx: mechanical and first thermal analysis.

Extensive exposure of the hand-arm system to regular vibration can lead to various disorders and injuries due in part to changes of mechanical quantities like dynamic stress or strain arising from the propagation of such vibration. Nowadays the direct measurement of this biodynamic response inside soft tissues is still a great issue, thereby finite element models have been developed in order to assess the dynamic mechanical variables by numerical computation. Despite previous modelling approaches succeeded in reproducing qualitative observations, they have not been fully correlated with experimental data. Our work aims at establishing and verifying a reliable high fidelity 3D finite element model allowing the simulation of mechanical and thermal effects generated by vibration transmitted to a statically preloaded distal forefinger phalanx. In particular, we wish to identify both the most suitable hyper-elastic and damping behaviour laws and their related parameters which best fit measured static and dynamic finger’s stiffness. A special attention was paid to the choice of a physiological and phenomenological damping law relevant for soft tissues since damping is directly linked to the dissipated mechanical power which could be partly responsible for the onset of hand-arm vibration syndromes.