def METHOD_NAME(self, structure_tstep, aero_tstep):
    # called by DynamicCoupled
    if self.settings['update_grid']:
        self.data.aero.generate_zeta_timestep_info(structure_tstep,
                                                   aero_tstep,
                                                   self.data.structure,
                                                   self.data.aero.aero_settings,
                                                   dt=None)