Based on the hybrid reasoning method of rule-based reasoning (RBR) and case-based reasoning (CBR)

this paper studies the intelligent design method of aircraft structural parts. Firstly

combined with fuzzy theory and rulebased reasoning technology

processing fuzzy parameters for aircraft structure parts design

and the intelligent selection system of aircraft structural parts is designed to realize the type selection of aircraft structural parts. Secondly

the K-nearest eighbor (KNN) and grey relation analysis (GRA) are used to deal with the numeric parameters of aircraft structural parts  design

and it implements cases retrieval and evaluation. Then the best similar cases are used for variant design to obtain the target case. Finally

the feasibility of the hybrid reasoning intelligent design system is verified by taking the section steel as an example.