Based on the functions and design requirements of aero-engine

the intensions of whole structure efficiency were elaborated in detail. Considering the load feature of whole structure

the evaluation parameters of whole structure efficiency were put forward from both the deformation resistance and dynamic environment adaptability. By establishing the normalization method of evaluation parameters such as rotor-to-stator clearance variation

strain energy distribution coefficient and sensitivity coefficient and the operation rule of structure efficiency coefficient

the analysis process of structure efficiency was defined. A structural efficiency assessment on low bypass ratio turbofan engine was conducted

by which the calculation process of the structure efficiency evaluation was given in detail. A structure scheme 2 was introduced based on the original structure scheme of the low bypass ratio turbofan engine

and then was compared with the original structure scheme based on the structure efficiency evaluation method. Result shows that the original structure is superior to the structure 2 both in the deformation resistance and the dynamic environment adaptability

and its structure efficiency coefficient is 0.11

which is higher than the structure 2

validating the practicability of the proposed structural efficiency evaluation method.