Author : Bansal Rajesh Kumar and Kumar Punit

 
This paper proposes a Hierarchical Data Structure (HDS) for modeling of non-manifold thin objects, consisting of seven nodes named as Thin Object, Sheet, Feature, Face, Part Edge, Edge and Vertex. This paper modifies and validates a general topological invariant s + eL + eNL + eFF +b + j – v – gn – fP – fNP- fFF = 0 regarding the number of sheets, linear edges, non-linear edges, freeform edges, bends, joints, vertices, non-manifold genuses, planer faces, non-planer faces and free form faces respectively for non-manifold thin objects. Corresponding Euler operators are derived, providing a basis for a modeling system for thin-walled objects.

Keywords: Non-manifold Thin Objects, Topological Invariant, B-Rep, Euler Operators.

Article published in International Journal of Current  Engineering  and Technology, Vol.3,No.3(Aug- 2013)