The cross-section design according to the invention allows the geometrical moment of inertia to be substantially increased as compared to conventional cross-section designs.

In order to solve the problem, a new algorithm for calculating RCS is presented based on the geometrical characteristic of target aircraft configurations and the method of moment (mom).

For conservative external nodal moments, the virtual work for the external moment can result in an external load stiffness matrix, which can significantly modify the geometrical stiffness matrix.