High-temperature digital image correlation techniques for full-field strain and crack length measurement on ceramics at 1200 °C: optimization of speckle pattern

Refractory materials are subjected to thermomechanical loads during their working life, and consequent creep strain and stress relaxation are often observed. In this work, the asymmetric high temperature primary and secondary creep behavior of a material used in the working lining of steel ladles is characterized, using uniaxial tension and compression creep tests and an inverse identification procedure to calculate the parameters of a Norton-Bailey based law. The experimental creep curves are presented, as well as the curves resulting from the identified parameters, and a statistical analysis is made to evaluate the confidence of the results.

ResumoO uso de ferramentas de simulação numérica para análise estrutural vem se expandindo nos últimos anos, sobretudo utilizando o método dos elementos finitos. Nesse trabalho são apresentados dois exemplos de otimização de projetos envolvendo componentes de mecanismos de válvula gaveta, realizados pela Magnesita Refratários S.A. Partindo da geometria inicial até o produto final, é analisado como o campo de tensões é adequado a valores admissíveis, conforme modificações de projeto são realizadas. Por fim, é demonstrada a importância desse tipo de estudo para alcançar maior confiabilidade e segurança em projetos mecânicos. Palavras-chave: Mecanismo de válvula gaveta; Simulação numérica; Análise estrutural. THE USE OF NUMERICAL SIMULATION TOOLS IN SLIDE GATE MECHANISMS'S DESIGN OPTIMIZATION AbstractThe use of numerical tools in structural analysis has grown in recent years, specially using the finite elements method. In this work, the design optimization of two slide gate system components are shown, performed by Magnesita Refratários S.A. Starting from the initial geometry until the final product, the adequacy of the stress fields to allowable values is analyzed as design is modified. Finally, the importance of this kind of study to achieve more reliable and safe mechanical design is established.