| Two major research objectives are to develop a comprehensive PC based environment for Multi-material CAD system for layered manufacturing (LM), which creates and handles models containing both geometrical model and material information; and to design and fabricate a portable reverse engineering hardware with associated computational tools to re-create surface and fabrication build models. The LM fabrication is a sequential process, which begins with the preparation of multi-material CAD model. This is followed by part fabrication and post-process. Any error in CAD will propagate in the following steps, therefore, it is very critical that CAD model generates accurate and defect free pre-fabrication parts. On the other hand, in an “E-manufacturing” environment, designers' PCs and LM systems can be the network nodes. They utilize digital data to communicate information each other. In order to construct the communication among designers' PCs and FDMC (Fused deposition for Multiple ceramics) machine FDMC-CAD framework is created. This system includes multi-CAD, RE (Reverse Engineering) system, and fabrication simulation. The task of FDMC-CAD is to assist designers to create a desired digital FDMC fabricated file. Once the digital fabricated file is created, it can be sent to FDMC machine directly through the network. The current advances in a self-contained multi-material CAD system include: (1) A new multi-material STL model was developed, which contains both geometrical model and material information. (2) A multi-material slicing process was designed and developed for slicing the multi-material model. (3) A road shape library was developed to associate with road deposition simulation in creating a virtual FDMC part. (4) A PC-based comprehensive CAD-FDMC system has successfully integrated multi-material model generation, slicing, tool-path generation, and road deposition simulation and road shape library. (5) A portable reverse engineering hardware with a computational control interface was designed and developed. (6) A series of four mesh algorithms were developed to quantify the reverse engineering data to create all necessary information to fabricate the scanned object. (7) The system was successfully evaluated on many example problems.; It is believed that this is one of the first developments in LM CAD where both forward and reverse engineering issues are addressed and developed. |
