Designing bionic surface grid structure with base structure method

To improve the efficiency of the composite material wing structure of a solar-powered UAV, this paper proposed an efficient discrete structural topological optimization method based on the notion of bionic design. The method considers the features of such wing structures as discrete stiffness, high aspect ratio and ultralight. Through multi-step optimization, the grid relationship of the base structure method is established with the GRAND method, so as to obtain the design space of discrete topological optimization. First, linear programming is used to solve optimization problems and thus gives the topological relations of a wing structure. Then, by extracting the information on node dimensions of the discrete topological structure, a bionic geometric model is established with the notion of bionic design. In order to obtain the optimal topological form of the bionic surface grid structure of the wing, the finite element analysis and the structural dimension optimization are carried out with the parameterization method. On the condition that design requirements are satisfied, the optimization reduces the weight of the wing by 34.4%, compared with the traditional design methods. Results show that the structural optimization method proposed in the paper is effective for this special composite material wing structure and can be used for the lightweight design of similar structures.