The bistable piezoelectric cantilever generator can sustain large-amplitude interwell oscillations over a wide frequency range.However,for energy harvesting,it is still a problem that which form of large-amplitude motion is the most desired behavior.In addition,how to obtain the mainly occurring condition of the most desired motion is a key problem.To solve this problem,the analytical formula of nonlinear magnetic potential energy is derived.Based on that,a coupled piezo-magneto-elastic distributed model of the bistable piezoelectric cantilever generator is proposed.The influence of the distance between the two magnets on the nonlinear properties is studied and the range of magnet distance which leads to the bistable states is obtained.Numerical simulation and experimental study are carried out to analyze the bifurcation,response characteristics and its impact on the electrical output performance under varying external excitations.Results indicate that,large-amplitude limit cycle motion with oscillations around two stable equilibrium points corresponds to optimum power output; the chaotic movement and the interwell motion includes the oscillations around one stable equilibrium point are less effective.At a given frequency,as the level of excitation increases,the phenomena of symmetric-breaking and amplitude-and phase-modulation are observed.Then,both period-doubling bifurcation and intermittency routes to chaotic motion in the bistable system are found.It can be seen that the power output is not proportional to excitation level because of the bifurcation behavior.The system power output doesnt change obviously when the system undergoes a sequence of period-doubling bifurcations and the onset of intermittency.The phenomena could be explained like this: the cross-well oscillation is still the main motion pattern of the cantilever at this point.As the level of excitation keep increasing,eventually the periodic behavior almost completely disappears and the response becomes fully chaotic,where the power output decreases obviously.