This paper deals with the harmonic oscillations of a periodically excited van der Pol system where hysteresis was simulated via fractional operator representations. The fractionally damped van der Pol equation was transformed into a set of fractional inte This paper deals with the harmonic oscillations of a periodically excited van der Pol system where hysteresis was simulated via fractional operator representations. The fractionally damped van der Pol equation was transformed into a set of fractional inte