Design and evaluation of fully configured models built by additive manufacturing

The cost and time relative to model building could be reduced considerably by the introduction of additive manufacturing. To evaluate the feasibility of the technique to build practical models, a real fighter was adopted as the prototype and a resin-metal hybrid model fully deployed with control surfaces was designed, validated, and tested in the paper. Connection structures that can ensure reliable connections and enable angle adjustment of control surfaces were designed in detail. Based on a careful worst-case analysis from computational fluid dynamics calculations, finite element analysis analyses for strength and stiffness validations were conducted, which shows the safety of the model in testing. First eigenfrequencies of the hybrid model and the metal model were calculated with the FEA method, and the comparison indicates resonance clearance improvement of the hybrid model duo to a remarkable weight reduction by nearly 50% to the metal one. Most aerodynamic coefficients of the hybrid model obtained from wind-tunnel testing are consistent with those of the metal model, from which it can be concluded that the hybrid model can replace metal models in the aerodynamic study for aircraft in the subsonic domain. The efficiency to build models was also improved significantly.