A parametric-associative Modelling of aeronautical concepts for structural optimization

Purpose: In this paper, an associative-parametric approach is proposed in order to model the mesh of an aeronautical concept starting from a set of high-level structural primitives. To assure orders of continuity higher than C0 between adjacent instances, a suitable mathematical description of the structural primitives has been identified. The maintenance of the continuity constraints must be assured when the mesh is modified. Method: The Bézier curve and the Coons surface patch, with a suitable degree, are used in order to assure orders of continuity higher than C0 in the connection points or edges. Appropriate schemes of dependences are identified to assure the automatic propagation of the modifications complying with the continuity constraints. Result: The approach here proposed allows the designer to carry out the geometric modelling and the automatic mesh generation within one software environment in a fast and interactive way and complying with the geometric continuity constraints and the one-to-one correspondence between the mesh elements. This represents evidently a large advantage since the structural optimization process is simplified, with a relevant man-hours saving. A lower number of data transfers between different software is, moreover, involved with less problems related to the data corruption. Finally low conceptual value operations, due to manual correction activity of the model, are eliminated. Discussion & Conclusion: The methodology here proposed allows the automatic propagation of modifications satisfying the geometric continuity constraints and the one-to-one correspondence between the mesh elements. The approach is implemented into a CAD/CAE tool, called MeshFEM and developed using C++ and Matlab languages and the VTK library for the 3D graphic visualization.