  We are interested in studying an unsteady fluid-structure interaction problem
in a three-dimensional space. We consider a homogeneous Newtonian fluid which
is modeled by the Navier-Stokes equations. Whereas the motion of the structure
is described by the quasi-incompressible non-linear Saint Venant-Kirchhoff
model. We establish the local in time existence and uniqueness of solution for
this model. For this sake, first we rewrite the non-linearity of the
elastodynamic equation in an explicit way. Then, a linearized problem is
introduced in the Lagrangian reference configuration and we prove that it
admits a unique solution. Based on the a priori estimates on the solution of
this problem together with the fixed point theorem we prove that the non-linear
problem admits a unique local in time solution. At last, by the inf-sup
condition we reach to the existence of the fluid pressure.
