Sound production in musical instruments is the consequence of
interactions and wave propagation that include nonlinear
phenomena. Simulating these phenomena will enable sound synthesis
softwares (such as Modalys, developed at IRCAM) to produce more
realistic sounds. In order to do so, nonlinear physical models will be
implemented in Modalys software using Green-Volterra kernels.

Green-Volterra kernels are used to simulate space-time nonlinear
dynamical problems. This formalism allows to keep the modal approach
and simulate nonlinear dynamics until a given order in the
Green-Volterra series. This numerical method has been chosen in order
to keep "near real-time" computation time. Interactions solving
requires to compute the inverse problem, i.e. compute a force using
known displacement or velocity. Green-Volterra kernels of a nonlinear
string model and interaction definition will be presented with
associated numerical results.