International Journal of Fracture

, Volume 209, Issue 1–2, pp 231–234 | Cite as

A degradation function consistent with Cocks–Ashby porosity kinetics

  • John A. Moore
Brief Note


The load carrying capacity of ductile materials degrades as a function of porosity, stress state and strain-rate. The effect of these variables on porosity kinetics is captured by the Cocks–Ashby model; however, the Cocks–Ashby model does not account for material degradation directly. This work uses a yield criteria to form a degradation function that is consistent with Cocks–Ashby porosity kinetics and is a function of porosity, stress state and strain-rate dependence. Approximations of this degradation function for pure hydrostatic stress states are also explored.


Degradation function Porosity Damage Ductile fracture Strain-rate dependence 



The author would like to thank Nathan Barton for his input and discussions regarding this work. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 (LLNL-JRNL-730381).


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Copyright information

© Springer Science+Business Media B.V. 2017

Authors and Affiliations

  1. 1.Lawrence Livermore National LaboratoryLivermoreUSA

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