The incremental harmonic balance nonlinear identification(IHBNID) is extended to high-dimensional nonlinear vibration system.The identification equation of multi-degree-of-freedom nonlinear dynamic system is derived.Numerical simulation on a two-degrees-of-freedom nonlinear system example,based on the IHBNID, was carried out on the period-1,the period-doubling and the chaotic motions.The effect of noise on the identification parameters is analyzed.The effectiveness of the IHBNID is verified for multi-degree...