International Journal of Science Technology & Management ISSN: 2321-774X Volume 3, Issue 2, July, 2015 www.avjournals.com 181 CONTOUR SUB-DIVISION ALGORITHM FOR GRADIENT REFERENCE APPROACH TO MODEL HETEROGENEOUS OBJECTS Vikas Gupta*, MED, CDLMGEC Panniwala Mota, 9416434412, vikasbrcm@rediffmail.com Rajesh Kumar Bansal, MED OITM Hisar, rajeshbansal73@gmail.com Vineet Kumar Goel, MED, OITM Hisar, vineet13ss@gmail.com Abstract The heterogeneous object consists of two or more materials with different characteristics with or without any specific boundary interface. The properties of the materials are controlled to functional requirement of the object. Rapid Prototyping processes have potential to fabricate such objects but require a CAD model with supplementary material information. The developed Gradient Reference approach has the capability to model the material distributions at different locations and assures the local control in the heterogeneous region. The approach presents a simple and efficient method to model the material distribution in heterogeneous objects. This paper focuses on exploring the contour sub-division algorithm to distribute the material in the object domain. The algorithm is capable of distributing the material in regular and irregular shape objects. The few examples are presented for validation of work. The developed approach is flexible and versatile to control the material composition at a location in HO. The material properties can also be evaluated for different material composition across the heterogeneous object. Keywords: Heterogeneous Objects, gradient reference, contour sub-division algorithm 1. Introduction Traditional CAD systems, used for conventional design method, can only represent the geometry and topology of an object. No material information is available within the representation which is required for heterogeneous objects. With the capability to fabricate heterogeneous objects, functionally efficient and cost reducing designs can be realized. Rapid prototyping (RP) techniques allow heterogeneous material objects to be produced using 3D CAD models by varying material composition region-wise, layer- wise, or point-wise. The required 3D CAD model should have not only the geometric information but also the information of material, property, etc. at each point inside an object. In order to take full advantage of the greatest potential of heterogeneous objects, one must have matching capabilities for their computer modeling, analysis, design optimization and visualization. The primary focus of the recent research development in these fields is on the computer representation schemes for heterogeneous objects, by extending the mathematical models and computer data structures of the modern solid modeling techniques to include discrete material regions of interfacial boundaries and heterogeneous properties. Recent studies show that an effective heterogeneous CAD modeling system should at least meet the various specifications [8]. Approaches of modeling of HO have been extensively studied in computer and manufacturing community. Kumar and Dutta [9-10] proposed an approach to model multi-material objects based on R-m sets and R-m classes primarily for application in layered manufacturing. Boolean operators were defined to facilitate the modeling process. Jackson [7] and Liu [11-12] proposed a local composition control (LCC) approach to represent heterogeneous object in which a mesh model is divided into tetrahedrons and different material compositions are evaluated on the nodes of the tetrahedrons by using Bernstein polynomials. Chiu [2] developed material tree structure to store different compositions of an object. The material tree was then added to a data file to construct a