Finite element analysis of the onset of necking and the post-necking behaviour during uniaxial tensile testing

Tensile deformation and post-necking behaviour were investigated using the elasto-plastic finite element method. Necking at the specimen centre could be reproduced by applying a radial constraint at the loading points without assuming initial imperfections or plastic instability theory. It was found from the calculated results that for strain hardening materials Hart's criterion overestimates the necking onset strain a little, probably due to the end effect.