A new computational method for MAT of injected parts integrated in part modelling stage

Vojislav Petrovic (1) , Pedro Rosado (2, 3) , Rafael Torres (4)

1 Product Engineering
2 Department of Mechanical Engineering
3 Department of Mechanical Engineering
4 Mechanical Engineering and Materials

In this paper we present a simple and fast approach for MAT generation in discrete form. It is used for manufacturability analysis in part modelling stage of injected parts. The method is a volume thinning method based on straight skeleton computation, modified and applied in 3D on B-rep models in STL. The volume thinning of B-rep model is based on its boundary surfaces offset towards model interior. The surfaces' offset is done with an adequately proposed offset distance which makes some of non adjacent offset model surfaces overlap (they “meet” in mid-surface or MAT). Offset surfaces are used to reconstruct the topology of a new B-rep model (offset model). Overlapping surfaces in offset model are detected, separated and aggregated to MAT. For adequate MAT precision and adequate MAT radius function, we propose to treat B-rep model concave edges (vertices) as cylinders (spheres) of zero-radius and offset them in adequate way. On these bases, we present an iterative algorithm in which MAT is being constructed in incremental way by consecutive volume thinning of obtained offset models. MAT construction is finished when an empty offset model is obtained. An algorithm has been created and implemented in Visual C++. Some of obtained results are presented in this paper.

Mots clés: Physical Sciences

Vojislav Petrovic, Pedro Rosado, Rafael Torres. A new computational method for MAT of injected parts integrated in part modelling stage. International Journal of Production Research, 2010, 48 (08), pp.2431-2447. ⟨10.1080/00207540802662912⟩. ⟨hal-00565391⟩