Hybrid structural layout of wing box for small aeroplane

The algorithm of optimization of the hybrid structural layout for the wing box has been developed. The wing box consisted of two parts; one of them (heavily loaded) had hybrid (lattice-truss) layouts, the other had conventional (black metal) layout. These parts was connected by use of interface structure. The basic objectives were sizing of load-bearing elements for each of the layouts, and to search for the interface position, providing minimum weight of the wing box structure. These tasks were solved with use of genetic algorithm. At searching for the interface optimal position the results of parametric FEM calculations were additionally used. A rational variant (65-73%) of the relative length of the wing box zone with lattice-truss structural layout has been obtained for the aircraft of regional airlines. This variant meets the constraints, and has the weight benefit (13-17%) compared with conventional structural layout.