Necking evolution in dynamically stretched bars: New experimental and computational insights Articles uri icon

publication date

  • June 2016

start page

  • 216

end page

  • 239

volume

  • 91

international standard serial number (ISSN)

  • 0022-5096

electronic international standard serial number (EISSN)

  • 1873-4782

abstract

  • This paper presents new results on dynamic neck evolution in steel bars of varying diameters. Dynamic tensile tests were carried out in a Kolsky apparatus using cylindrical steel specimens with various cross-section diameters ranging from 1.5 mm to 4 mm. A high speed digital camera was used to record the deformation of the specimen during the loading process. Video recording of the tests enabled accurate experimental measurements of the necking evolution, specifically its growth rate as a function of the diameter. The experiments show that increasing the specimen cross-section slows down the neck development. This behavior has been further investigated using two different kinds of numerical calculations: (1) axisymmetric finite element simulations and (2) one-dimensional finite difference computations.

keywords

  • dynamic necking; necking growth rate; dynamic tensile experiments; numerical calculations; stress multiaxiality; hopkinson pressure bar; adiabatic shear bands; high-strength steels; loaded tensile bars; high-strain rates; ductile materials; rate extension; localization; fragmentation; bifurcation