By default, the initial guess of the nonlinear multiharmonic solver is a zero initial condition. You can specify an initial guess by issuing HBMOPT,UINIT. Example 3: Two Jointed Beams with Frictional Contact Interface shows how to define the initial solution vector from a previous analysis. For instance, a prior static solution can be used as an initial guess for the zeroth harmonic nodal displacements, which helps improve convergence.