finite difference method; intrinsic equations for beams; numeric stability
Intrinsic equations represent promising approach for the description of rotor blade dynamics. They are the system of non-linear partial differential equations. Stability of numeric solution by the finite difference method is described. The stability is studied for various numerical schemes with different methods for the computation of spatial derivatives from time level $n+0.5$ (i.e., mean values of old and new time step) to $n+1$ (i.e., only from new time step). Stable solution was obtained only for schemes between $n+0.55$ and $n+0.9$. This does not correspond to the assumption that more implicit schemes have more numeric stability.