Recursos CAD/CAM voltados ao modelamento e a usinagem de cavidades para moldes, com estudo de casos de aplicação

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro TecnologicoÉ notório, e cada vez mais crescente, a substituição de diversos materiais existentes no mercado pelo plástico, principalmente na área da engenharia. Associado a este crescimento, aumentam as exigências sobre os produtos de plástico, em termos de qualidade, preço, formas geométricas mais complexas e tolerâncias cada vez mais apertadas. Somado-se isto, também tem-se exigido prazos cada vez menores para um novo produto chegar ao mercado. Estes fatores vêm pressionando os fabricantes de moldes a procurarem novos métodos de fabricação em substituição aos meios tradicionais, visto que estes estão cada vez correspondendo menos a estas exigências. O auxílio do computador, na fabricação de moldes, vem sendo uma solução pretendida por estas empresas, através das tecnologias CAD/CAM, a exemplo dos bons resultados alcançados por outras áreas. As primeiras implantações destas tecnologias, no entanto, demonstraram que os sistemas precisam ser adaptados ao setor, devido principalmente, às necessidades peculiares

Accuracy Effects of Shelling a Part in the SLS Process 306

In order to reduce SLS process time in the manufacture of a mould insert, the idea of shelling the geometry of the insert has been tested. Some shelling strategies have been successful with the RapidToolTM process, proving the feasibility of the idea. It has been observed in the tests, for both polymer and RapidSteel2.0TM materials, that size accuracy, particularly of small features in the scanning (X) direction, depends on vector length (VL). When a sudden change in VL occurs, this leads to steps on the sintered surface. This paper presents both experimental observations of this and simulation results from a finite element model.Mechanical Engineerin

Parallel tool-path generation for Additive Manufacturing: A GPU-based zigzag filling

This paper presents a parallel zigzag (raster) tool-path generation method for Additive Manufacturing (AM). Based on the analysis of some ordinary serial algorithms, it was observed that some compute-intensive operations could be parallelized by using a Graphics Processing Unit (GPU) architecture. However, to achieve this, many challenges were faced and solved by designing a method to work concurrently with individual contour segments on multiple layers while keeping the data organized. The method’s ability to solve the zigzag generation problem was verified, and its performance was measured by running an exhaustive search for optimal raster angles to reduce manufacturing time. The results showed that the method was effective and generated relevant computational gain, being up to 9 times faster than its serial counterpart. In the tool-path optimization, the simulations found configurations yielding an average length of raster lines up to 38% longer, which, in turn, can reduce manufacturing time