Development of 3D Advanced Rapid Prototyping Multipurpose Structures with Micro and Nano Materials

摘要

In various areas of manufacturing, research and education, the 3D rapid prototyping methods are widely employed. Typical applications are engineering, architecture, medicine. The present technical and commercial demand requires the development of faster and cheaper methodologies for structures design and realization. Different techniques, based on CAD platforms and Rapid Prototyping (RP) are available. The conceptual steps of the design are: theoretical and FEM analysis, virtual 3D CAD model, RP shape processing. The RP method allows to produce also simulacra (demonstrators and prototypes) useful to analyze the characteristic of a complex system (ex. interference between the dynamic parts, cinematic behavior, geometric evaluation, quality and reliability). The RP elements produced normally are moulds (for metal casting but also for RTM (Resin Transfer Molding) process of polymeric composite materials) or mandrel for Filament Windings processes. The limits of the RP are the time requested by the process and the limited volume of the samples producible. The target of the present work is the development of an automatic RP procedure, useful to produce high quality and complex geometry components, characterized by high material yield, significant reduction in the manufacturing time and low final cost. In particular, the Authors discuss the innovative realization of advanced lattice multigrid structures for aerospace applications, made of polymeric composite materials (PCM) and of metallic alloys. The properties of prototyped samples and structures are evaluated by mechanical test (static and dynamic). PCM lattice structures were realized by Filament Winding (FW) on a negative mould (mandrel) produced by Stereo Lithography (SLA). A numerical model of the RP curing phase is discussed. The use of micro and nanostructured polymeric composite materials is moreover illustrated. The addition of nano particles gave an improvement of mechanical properties.