A processing algorithm for freeform fabrication of heterogeneous structures

A processing algorithm for freeform fabrication of heterogeneous structures is presented. The algorithm was developed based on the heterogeneous fabrication structural model, which was constructed from the STL based multi-material volume regions and with material identifications. The reasoning Boolean operation based modelling approach was used to construct the heterogeneous CAD assembly and to output the needed STL format. Procedures for generating the database hierarchy and the storage of the heterogeneous structural model, and derivation for developing the processing algorithm for layered fabrication of heterogeneous structure are presented. The developed algorithm was applied to a heterogeneous structure consisting of two discrete material volumes, and the detailed processing path is described.