Uni-axial stress–strain characterisation of silicone composite specimens derived from vocal folds replicas

Abstract

A-priori knowledge of the uni-axial stress–strain behaviour of molded silicone multi-layer composite vocal folds replicas would benefit their structural design and favour their usage in physical studies of voiced speech sound production. Therefore, recently a model approach of the linear and continuous non-linear stress–strain behaviour of silicone composites is validated, for which the generic parameters are shown to depend only on the effective low-strain Young’s modulus of the homogenised composite. Whereas previous work focused on extensive model validation in terms of layer’s stacking and composition, in this work the model approach and uni-axial tension testing are used for the stress–strain characterisation of six molded silicone composite specimens derived from three vocal fold replicas. For each replica, measured and modelled effective low-strain Young’s moduli are determined, the non-linear behaviour is assessed and a criterion is proposed to identify the onset strain and effective Young’s modulus associated with a linear high-strain region and thus to extend the model approach to the high-strain region. It is concluded that the non-linear stress–strain behaviour of composite specimens can be predicted, solely based on the knowledge – either measured or modelled – of the effective low-strain Young’s modulus of the equivalent homogenised composites. Consequently, uni-axial stress–strain behaviour can be taken into account for the structural design of silicone composites and associated multi-layer silicone vocal fold replicas.