Contribution to the physical modeling of the lips. Influence of the mechanical boundary conditions

A new model for the simulation of brass player lips is presented. This model is based on in-vitro experiments carried out on mechanical lips replica. In this set-up, particular attention is paid to the mechanical boundary conditions of the lips. The pressing of the mouthcup against the lips of the player is carefully reproduced. Two kinds of study are carried out. In the first, static study, experimental results are compared to numerical simulations based on a two-mass model of the lips. It is shown that the coupling stiffness between the two masses has to be negative in order to account for volume conservation of the lip tissues. In the second, dynamic study, parameters of the two-mass model are determined with a minimum of ad-hoc assumptions. A linear stability analysis of the two-mass model including negative coupling stiffness is carried out. It fails to reproduce the measured dynamical behaviour of the lip replica. That tends to show that the two-mass model is not able to account for actual mechanical boundary conditions