Palavra-chave: BIFURCATION

NON-SMOOTH VECTOR FIELDS SINGULARITY CLOSED ORBIT CENTER LIMIT CYCLE AVERAGING NONSMOOTH DYNAMICAL SYSTEMS NORMAL FORM ASYMPTOTIC STABILITY STRUCTURAL STABILITY CYCLE SHILNIKOV PROBLEM VERSAL UNFOLDING DISCONTINUOUS VECTOR FIELD FILIPPOV SYSTEMS FOLD-FOLD LOOP STABILITY REFRACTIVE VECTOR FIELD FIRST INTEGRAL PERIODIC ORBIT DIFFEOMORPHISM VECTOR FIELD REGULARIZATION HAMILTONIAN