Modelagem de fratura em materiais compósitos por métodos de elementos finitos

• Autor(a) principal: Maciel, Maísa Milanez Ávila Dias [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155344; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-04-18/000882007.pdf
• topic: Mecânica da fratura; Análise de elementos finitos; Materiais compostos; Fracture mechanics

Composite materials have been widely used in recent years in structural applications, such as the Boeing 787 - Dreamliner. Thus, the understanding of failure methods of composites is necessary in order to predict their mechanical behavior under loading. Thereby, computational modeling has become a great advantage in the area, with new constitutive laws and more realistic models increasingly approaching to materials mechanical behavior. This work has started the development of a model for predicting the fracture of composites using open source software. It was modeled a 2D lamina of unidirectional carbon fiber and epoxy composite laminate. The lamina was considered isotropic in the simulation, in order to get used to the computational environment. Three meshes were designed in the GiD software, each one had different element sizes. The different meshes illustrated the refining effects on the simulation results and the computational cost. Seven different stress conditions were tested 20, 250, 500, 700, 1000, 1500 and 1700 MPa. The various tensile stresses show, firstly, the variation of accumulated stress in the lamina and, secondly, it showed the stress range in which the model fit the real condition. It was observed that with the decrease of elements size the computational cost increases but it showed a smooth stress transitions in the obtained map. In addition, the model was not stable in predicting stress accumulation for stresses lower than 700 MPa. Although materials, which have an elastoplastic response to stress, tend to take some time to respond to initial application of load, the Von Mises criterion is more representative for the plastic state, especially the upper boundary