General results concerning suppression of homoclinic (and heteroclinic) cha
os are derived on the basis of a Melnikov analysis for damped, nonlinear, a
nd low-dimensional oscillators subjected to two weak harmonic excitations (
one chaos-inducing and the other chaos-suppressing). Analytical expressions
are deduced for the intervals of initial phase difference between the two
excitations for which chaotic dynamics can be eliminated. It is demonstrate
d that {0, pi/2, pi ,3 pi/2} are, in general, the only optimal values of su
ch phase differences, in the sense that they allow the widest amplitude ran
ges for the chaos-suppressing excitation. (C) 1999 Published by Elsevier Sc
ience B.V. All rights reserved.