156 research outputs found

    Numerical thermo-elasto-plastic analysis of residual stresses on different scales during cooling of hot forming parts

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    In current research, more and more attention is paid to the understanding of residual stress states as well as the application of targeted residual stresses to extend e.g. life time or stiffness of a part. In course of that, the numerical simulation and analysis of the forming process of components, which goes along with the evolution of residual stresses, play an important role. In this contribution, we focus on the residual stresses arising from the austenite-to-martensite transformation at microscopic and mesoscopic level of a Cr-alloyed steel. A combination of a Multi-Phase-Field model and a two-scale Finite Element simulation is utilized for numerical analysis. A first microscopic simulation considers the lattice change, such that the results can be homogenized and applied on the mesoscale. Based on this result, a polycrystal consisting of a certain number of austenitic grains is built and the phase transformation from austenite to martensite is described with respect to the mesoscale. Afterwards, in a two-scale Finite Element simulation the plastic effects are considered and resulting residual stress states are computed

    Pragas da oliveira.

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    Efeito de iscas tóxicas sobre o parasitoide Diachasmimorpha longicaudata (Hymenoptera: Braconidae).

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    O objetivo do trabalho foi avaliar o efeito de iscas tóxicas sobre o parasitoide D. longicaudata por meio de testes por ingestão

    Monitoramento de Curculionidae em talhão de nogueira-pecã (Carya illinoensis) (Wangenh.) K. Koch, em Candiota/RS.

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    O presente estudo visa contribuir no conhecimento de espécies broqueadoras de Coleoptera presentes em plantio de nogueira-pecã no estado do Rio Grande do Sul
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