SHAPE OPTIMIZATION OF 3-DIMENSIONAL PARTS BASED ON A CLOSED-LOOP BETWEEN STRUCTURE-ANALYSIS AND GEOMETRIC MODELING

Optimization of three-dimensional parts is viewed here as optimization of the real design parameters found in geometric modellers, thus ensuring a parr is usable in any further CAD treatment. Use of such a technique within the industrial design process is discussed. The B-Rep modelling technique forms the basis for the part geometry parameters. Design parameters are chosen or built up from these. A bi-directional link between surface description and location of nodes is described and provides good compatibility between the boundary geometry and the mesh throughout the optimization loops. Thus, objective and constraint functions both come from structure analysis and geometry implications. The necessary gradient computation of a mechanical criterion with respect to node location is processed by a method using an adjoin equation and a material derivative approach. An existing industrial mechanical solver can then be used, without any change being necessary: each development is performed using CAD software.