Post necking characterisation for sheet metal materials using full field measurement

作者：Marth Stefan; Haggblad Hans Ake; Oldenburg Mats; Ostlund Rickard

来源：Journal of Materials Processing Technology, 2016, 238: 315-324.

DOI：10.1016/j.jmatprotec.2016.07.036

• Localised necking
• Stepwise modelling
• Optical full-field measurement
• Hardening characterisation
• Boron steel

A precise prediction of the post-necking behaviour of materials is needed to increase the precision of computer simulations with large deformations. Applications in which this need is encountered include crash, forming, and failure simulations. By using an optical full-field measurement of the localised deformation field, an effective and computationally fast method is presented to determine the relationship between true stress and true plastic strain, including post-necking behaviour. The presented stepwise modelling method is used to characterise heat-treated boron steel using thin sheet metal specimens. These results are validated with the results determined by a method based on inverse modelling. It can be concluded that the stepwise modelling method is considerably faster than the compared inverse modelling method. The method is also suitable for effectively determining element size dependency due to regularisation of the hardening behaviour needed for finite element analysis with strain localisation, e.g., for crash simulations.

• 出版日期2016-12