Optimal Design of Unitized Panels with Curvilinear Stiffeners

This paper summarizes some numerical results of optimal design study of curvilinear stiffened panels where the reference axes of the stiffeners can be curvilinear. An integrated approach to use different capabilities in relevant fields, such as NURBS, DistMesh, and MSC.NASTRAN, etc., are adopted in the MATLAB environment. Numerical studies on optimal stiffened panel designs of buckling dominant problems are made to look into the effects of certain factors, such as, orientation, spacing, location, and curvature, etc., on the optimal designs. It is observed that curvilinear placement of stiffeners plays the role of orientation, spacing, location and intersection placement of infinitesimal straight stiffeners, and provides an enhanced design space. This enhanced design space may lead to better designs than using straight stiffeners though it is not always so. This work reveals the necessity to use global optimization techniques to perform topology/placement/shape optimization of curvilinear stiffened panels along with size optimization.