Non-uniform deformation after prestrain

• Autor(a) principal: Fernandes, José-Valdemar
• Data de Publicação: 2000
• Outros Autores: Menezes, Luis F., Rodrigues, Dulce M., Chaparro, Bruno M., Vieira, Manuel F.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/4308; https://doi.org/10.1016/S0997-7538(99)00146-1
• topic: tensile deformation; plastic instability; complex strain paths

The deformation behaviour of prestrained metal sheets is analysed in this work. The non-uniform deformation observed during reloading in tension was studied, by following deformation in different regions of the samples. It takes into account the presence of geometrical defects in the samples and explains the importance of mechanical behaviour. A simplified analysis was used, to model the behaviour in tension of a metallic specimen with geometrical imperfection. The flow behaviour is described using a Swift law equation, which includes strain-rate sensitivity. A modified law was used for prestrained materials and this incorporates the plastic prestrain value, adjusted to the path change. The model predicts imperfection growth kinetics with strain, and strain saturation in the homogeneous region, due to the onset of necking.