Qualitative analysis of van der pol type equation with periodic forcing term

AbstractIn this paper we analyze the qualitative behaviour of the equation $$\varepsilon \ddot X + q(X) \dot X + \varepsilon X = b p (t)$$ , whereε is a small parameter. We divide the interval of parameterb into four sets of subintervals.A, B, C andD. Forb∈A, B orD, we discuss the different structures of the attractors of the equation and their stabilities. When chaotic phenomena appear, we also estimate the entropy. Forb∈C, the set of bifurcation intervals, we analyze the bifurcating type and get a series of consequences from the results of Newhouse and Palis.