To enhance the understanding of the dynamic behavior of the low pressure rotor and structural fuse in three-shaft high bypass ratio turbofan engine during a fan blade off （FBO） event

the Trent 900 was selected as the research sample.The structural characteristics which may cause important influence was analyzed

and the research on the influence of the dynamic coupling between the rotors

the simulation of structural fuse

and fan blade simplification was conducted. The three-dimensional rotor/stator simplified model for the FBO simulation was built. The simulation of 360 degree rotating of the fan rotor was performed and compared with the video of Trent 900 engine FBO rig test. The results revealed that: (1) the simulation results matched the video of FBO rig test in the time sequence of macro phenomena. (2) The breakage of main structural fuse can reduce the output vibration load by about 45%. (3) Secondary structural fuse can form a new front support for the low pressure rotor and protect the fan shaft.