A two step optimization process is described to develop the distribution of materials and geometry for flexible skins. The skins are able to handle out-of-plane loads associated with aerodynamic loading while simultaneously allowing a wing substructure to under go large structural deformations. This requires the skin to simultaneously have low in-plane stiffness and high bending stiffness. The first step involves determining the bulk material properties required from the skin and the geometry describing the attachment to the substructure. For this step, a 3-layer physical model is described that takes in to account the structural mechanism, skin, and mechanism-skin connections in addition to aerodynamic loads. The optimization problem is developed using the Solid Isotropic Material Penalization method. Results from this step are the distribution of bulk material properties across a model wing structure. The next step assumes that the skin is a heterogeneous material. An optimization process is described based on a multi-objective function which minimizes the sum of the strain energy and mutual potential energy. An example is presented for a skin element subjected to deformation under shear loading as the wing is sweep in shear.
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