The steady-state responses of damped periodic systems with finite or infini
te degrees-of-freedom and one nonlinear disorder to harmonic excitation are
investigated by using the Lindstedt-Poincare method and the U-transformati
on technique. The perturbation solutions with zero-order and first-order ap
proximations, which involve a parameter n, i.e., the total number of subsys
tems, as well as the other structural parameters, are derived. When n appro
aches infinity, the limiting solutions are applicable to the system with in
finite number of subsystems. For the zero-order approximation, there is an
attenuation constant which denotes the ratio of amplitudes between any two
adjacent subsystems. For the zero-order approximation, there is an attenuat
ion constant which denotes the ratio of amplitudes between any two adjacent
subsystems. The attenuation constant is derived in an explicit form and ca
lculated for several values of the damping coefficient and the ratio of the
driving frequency to the lower limit of the pass band. [S0021-8936(00)0110
1-6].