Combining density-based approach and optimization refinement in the design of morphing airfoil structures

This paper presents a two-step optimization-based hierarchical approach for the morphing trailing edge structure design. In the first step, a density-based topology optimization method is used to obtain an initial topology of morphing structure. Specially, a linear finite element method is adopted for modeling the static problem, where the densities of elements are used as design variables. The objective of the first step is to minimize the least-square error between the deformed and the target airfoils. In the second step, the initial solution is refined through the optimization process which is set up by a more accurate modeling and nonlinear finite element analysis. By adjusting sizing variables and connecting points of the internal compliant mechanism, a significant reduction in stress of the compliant structure is achieved.