Optimization of wing structures to satisfy strength and frequency requirements

In this investigation minimum weight design of wing structures with restrictions on strength, stability and frequency characteristics is attempted. The multiweb delta wing structure is idealized with three different kinds of finite elements. The constant stress triangular plate elements, the rectangular shear panels and pin jointed bar elements are used to represent, respectively, the cover skins, webs and the stringers of wing structures. A parametric study is made to reduce the number of design variables which in turn reduces the required computational effort. The feasibility of employing linearly approximated redesigns is investigated. Numerical results are presented to illustrate the feasibility. Off-design charts have been obtained by performing sensitivity analysis about the final optimum design point.