Palavra-chave: LIMIT CYCLE

BIFURCATIONS SISTEMAS DINÂMICOS BROWER THEORY CENTER INTEGRABLE SYSTEMS POLICYCLE PIECEWISE SMOOTH SYSTEMS DULAC PROBLEM LIAPOUNOV-SCHIMIDT REDUCTION SINGULARIDADE ASYMPTOTIC STABILITY INVARIANT VARIETY EQUILIBRIUM LIENARD EQUATION NONSMOOTH DYNAMICAL SYSTEMS AVERAGING HAMILTONIAN ATTRACTOR INVARIANT TORUS AVERAGING METHOD ISOCHRONOUS CENTER LINEAR VECTOR FIELD PENDULUM REGULARIZATION MINIMAL SET NON-SMOOTH VECTOR FIELDS SYNCHRONIZATION PERIODIC ORBIT AVERAGE ESTABILIDADE ESTRUTURAL BIFURCATION SINGULARITY