  Optimization of thin-walled structures like an aircraft wing, aircraft
fuselage or submarine hull often involves dividing the shell surface into
numerous localized panels, each characterized by its own set of design
variables. The process of extracting information about a localized panel (nodal
coordinates, mesh connectivity) from a finite element model, input file is
usually a problem-specific task. In this work, a generalized process to extract
localized panels from the two-dimensional (2D) mesh is discussed. The process
employs set operations on elemental connectivity information and is independent
of nodal coordinates. Thus, it is capable of extracting panel of any shape
given the boundary and thus can be used during optimization of a wide range of
structures. A method to create stiffeners on the resulting local panels is also
presented, and the effect of stiffener element size on buckling is studied. The
local panel extraction process is demonstrated by integrating it into a
distributed MDO framework for optimization of an aircraft wing having
curvilinear spars and ribs (SpaRibs). A range of examples is included wherein
the process is used to create panels on the wing-skin, bounded by adjacent
SpaRibs.
