The topological optimization technology based on the variable density method was introduced into the design of aero-engine external support structure (such as accessory support). Taking the total flexibility under multiple working conditions as the objective function and the volume as the constraint function

the structural design of an engine support based on the topological optimization was carried out. The initial model of the bracket was established according to the relative position relationship between the engine casing and the accessories

and the stress analysis of the external support structure of the engine was carried out. The design method of the external support structure of the engine was established based on the topology optimization under multi load conditions and the size optimization considering the influence of strength. The strength

vibration and profile of the final support structure were checked and evaluated. The results showed that the maximum stress of the final model appeared in condition 3

and the maximum principal stress was 345 MPa

which was lower than the fatigue limit of the material; the first natural frequency of the bracket was more than 125 times of the maximum speed frequency of the engine. This method was used to optimize the topology of the external support structure of an engine. On the premise of meeting the requirements of strength

vibration and contour

the final model weight was only 73% of the original model. The optimization results based on multi operating conditions are more in line with the actual working requirements of the engine

and the research of this method has a bright future in engineering application.