Abstract : Stratoconception is a patented rapid prototyping process. It allows the direct manufacturing of a CAD model, layer after layer, without any lag in the design/manufacturing workflow. The Stratoconception process was developed by CIRTES since 1990 and is protected by relevant trademarks and international patents.
This process consists in breaking the part down, by Computing, into a set of straightforward elementary layers called stratum, in which stiffeners and strengthening plugs are inserted. The elementary parts are identified and then directly manufactured by 2.5 axis rapid milling, or by 5 axis laser cutting from sheet material. These elementary parts are the fitted together and imbricated in order to rebuild the final part. The assembly of the strata is considered from the design step to help withstand the mechanical constraints during use.
This work follows the CIFRE thesis n°642/99 prepared by Geoffroy LAUVAUX at the IFTS (Reims, France) and attended in 2005.
A lot of work was published about decomposition of model. At the beginning, the entities were used in the context of machining (of plane, cylinder,...). Nowadays, the decomposition is applied in the field of multimedia visualization, similarities recognition or conception of new models by using database of existing models.
In Stratoconception, we identify three types of decomposition, each of one responding to specific problem: decomposition in strata, pieces of strata and entities. Each of these decomposition solves accessibility, reduction of model's size and speed up of manufacturing time problems.
We work more specifically on the optimization of slicing procedure by using critical points and on the manufacturing of tubular models by using parting line. We also study the decomposition of model into nearly convex entities in 2D and 3D.