We discuss how the presence of frustration brings about irregular behaviour in a pendulum with nonlinear dissipation. Here frustration arises owing to the particular choice of the dissipation. A preliminary numerical analysis is presented which indicates the transition to chaos at low frequencies of the driving force.
G. Ambika and Dr. V . M. Nandakumaran, “Frustrated limit cycle and irregular behaviour in a nonlinear pendulum”, 1990.