Résumé
The double chain model (DCM) generalizes the Frenkel-Kontorova model for composite systems, coping with situations when both subsystems are deformable. We show how the shape and amplitude of the intermodulation of subsystems depend on the intersubsystem interaction potential, elastic constants, and average repeat distances of the subsystems. We characterize and study the behavior of the sliding mode, that is a pseudo-Goldstone mode of the system. DCM undergoes an analyticity breaking transition that leads to intrinsic pinning of the sliding mode, when the strength of the intersubsystem coupling is increased above a threshold value. [S0163-1829(99)02042-1].