Bio-inspired feature-driven topology optimization for rudder structure design

A fish operculum bone is a high-efficiency load-carrying structure, which transfers the surface pressure of the fluid through the special supporting structures on the thin-walled panel to the joint position connecting the body. In order to bring this concept of bionic structures into the flight vehicle rudder structures’ optimization design, problems such as the structural feature and parameterized modeling, load-carrying behaviors analysis, optimization design method, performance evaluation etc. need to be properly solved. To this end, we studied the operculum structure and found that the properly distributed Y-shape structural branches undertake the surface load perfectly. Meanwhile, the influence of these Y-shape branches distribution was discussed with numerical simulation and topology optimization. By considering the Y-shape branches as a special structural features, the bio-inspired design procedure was then established by integrating the structural layout and sizing parameters as well as their simultaneous feature-driven optimization. We also designed a typical flight vehicle rudder structure and fabricated it with stereolithography based resin additive manufacturing. With more than 20 % improvement in stiffness and strength compared with the traditional design, the advantages of the bio-inspired optimization have been clearly demonstrated.