An approach to modeling & representation of heterogeneous objects

Heterogeneous objects, composed of different materials, are increasingly being used in engineering applications. Also, a new fabrication method called Layered Manufacturing (LM) has shown potential to manufacture these objects. In order to manufacture heterogeneous objects by LM, a CAD model is required that contains both geometry and material information. However, current solid modeling techniques focus on capturing the geometric information only. In this paper, we present an approach to model and represent heterogeneous objects by integrating the material information along with the geometry/topology in the solid model. We define new modeling operations for creating and manipulating heterogeneous models and to complement traditional modeling operations. We also address the issue of computer representation of these new models. Finally, the issue of fabrication of these heterogeneous objects by LM is discussed.