<p>Ispitivan je generalisani Frenkel-Kontorova model pod&nbsp;dejstvom spolja&scaron;njih periodičnih sila,&nbsp;i njihov uticaj na &Scaron;apiro stepenike.&nbsp;Deformacija substratnog potencijala prouzrokuje&nbsp;pojavu velikih polucelih i drugih subharmonijskih&nbsp;stepenika u sistemu.&nbsp;Rezultati dobijeni u radu su od značaja&nbsp;u talasima i spinovima gustine naboja&nbsp;kao i u Džozefsonovim spojevima.</p> / <p>Properties of the Shapiro steps in dierent<br />commensurate structures of the ac + dc driven<br />Frenkel-Kontorova model with dierent generalized<br />substrate potential have been examined.<br />Deviation from the sinusoidal potential produces<br />appearance of large subharmonic steps.<br />Presented results could be of great importance<br />for thestudies of all real systems closely related<br />to the dissipative dynamics of the FK model<br />such as studies of the charge- or spin-density wave<br />systems and the systems of Josephson-junction arrays.</p>