A numerical strategy for finite element modeling of frictionless asymmetric vocal fold collision

Abstract

Document Version Peer reviewed version Link back to DTU Orbit Citation (APA):Granados, A., Misztal, M. K., Brunskog, J., Visseq, V., & Erleben, K. (2016) . SUMMARYAnalysis of voice pathologies may require vocal fold models that include relevant features such as vocal fold asymmetric collision. The present study numerically addresses the problem of frictionless asymmetric collision in a self-sustained three-dimensional continuum model of the vocal folds. Theoretical background and numerical analysis of the finite-element position-based contact model are presented, along with validation. A novel contact detection mechanism capable to detect collision in asymmetric oscillations is developed. The effect of inexact contact constraint enforcement on vocal fold dynamics is examined by different variational methods for inequality constrained minimization problems, namely the Lagrange multiplier method and the penalty method. In contrast to the penalty solution, which is related to classical spring-like contact forces, numerical examples show that the parameter-independent Lagrange multiplier solution is more robust and accurate in the estimation of dynamical and mechanical features at vocal fold contact. Furthermore, special attention is paid to the temporal integration schemes in relation to the contact problem, the results suggesting an advantage of highly diffusive schemes. Finally, vocal fold contact enforcement is shown to affect asymmetric oscillations. The present model may be adapted to existing vocal fold models, which may contribute to a better understanding of the effect of the non-linear contact phenomenon on phonation.

Vocal fold contact pressure in a three-dimensional body-cover phonation model

“…Computational models allow parametric variation of the geometry and mechanical conditions of the vocal folds and observing their effect on the contact pressure. Compared with lumped element models (e.g., Story and Titze, 1995), phonation models based on continuum mechanics allow examination of the contact pressure at a much finer resolution (Jiang et al, 1998;Gunter, 2003Gunter, , 2004Tao et al, 2006;Tao and Jiang, 2007;Bhattacharya andSiegmund, 2014, 2015;Granados et al, 2017). Computational models also allow investigation of the mechanical stress within the vocal folds that is otherwise difficult to measure in experiments.…”

Pathological Voice Source Analysis System Using a Flow Waveform-Matched Biomechanical Model

“…Denervation or organic diseases of vocal cords, such as paralysis and polyps, can cause irregular vibration with consequential changes, manifested as breathy or hoarse voice. These diseases generally affect one side of vocal structure, causing significant imbalance in bilateral vocal cord tension [ 1 , 2 ]. Irregular vibration of the vocal cords corresponding to a variety of voice disorders can be observed with electronic laryngoscope to assist diagnosing vocal cord disease.…”