Identification of the critical wavelength responsible for the fragmentation of ductile rings expanding at very high strain rates Articles uri icon

publication date

  • June 2013

start page

  • 1357

end page

  • 1376

issue

  • 6

volume

  • 61

international standard serial number (ISSN)

  • 0022-5096

electronic international standard serial number (EISSN)

  • 1873-4782

abstract

  • This work examines the mechanisms governing the fragmentation of ductile rings expanding at very high strain rates. Based on previous works three different methodologies have been addressed, namely: fully 3D finite element computations of the radial expansion of ductile rings, numerical simulations of unitary axisymmetric cells with sinusoidal spatial imperfections subjected to tensile loading and a linear perturbation technique derived within a quasi-1D theoretical framework. The results derived from these three different approaches allow for identification of a critical wavelength which dictates the fragmentation of ductile rings expanding at very high strain rates. This critical wavelength is revealed quite independent of the material properties but closely related to the ratio (L-0/phi(0))(critical) approximate to 1.5 where L-0 is the fragment size and phi(0) is the diameter of the circular section of the ring. This work highlights the fundamental role played by material inertia in the fragmentation at very high strain rates, setting aside the mechanisms associated to the classical statistical theories.

keywords

  • critical wavelength; very high strain rates; fragmentation; numerical simulations; stability analysis