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The paper of Prof. Petros Sofronis and Dr. Brian Somerday was published in "The Journal of The Minerals, Metals & Materials Society (TMS)".

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The paper of Prof. Petros Sofronis (Direcor, Principal Investigator, Hydrogen Materials Compatibility Research DivisionI²CNER), Dr. Brian Somerday (Lead Principal Investigator, Hydrogen Materials Compatibility Research DivisionI²CNER), and their collaborative research group was published in “The Journal of The Minerals, Metals & Materials Society (TMS)” in August 2014.

 

■ Outline

The failure of hydrogen containment components is generally associated with subcritical cracking. Understanding subcritical crack growth behavior and its dependence on material and environmental variables can lead to methods for designing structural components in a hydrogen environment and will be beneficial in developing materials resistant to hydrogen embrittlement. In order to identify the issues underlying crack propagation and arrest, we present a model for hydrogen-induced stress-controlled crack propagation under sustained loading. The model is based on the assumptions that (I) hydrogen reduces the material fracture strength and (II) crack propagation takes place when the opening stress over the characteristic distance ahead of a crack tip is greater than the local fracture strength. The model is used in a finite-element simulation of crack propagation coupled with simultaneous hydrogen diffusion in a model material through nodal release. The numerical simulations show that the same physics, i.e., diffusion-controlled crack propagation, can explain the existence of both stages I and II in the velocity versus stress intensity factor (V–K) curve.

 

■ Paper

* Title: On Modeling Hydrogen-Induced Crack Propagation Under Sustained Load

* Authors: Mohsen Dadfarnia, Brian p. Somerday, Philip E. Schembri, Petros Sofronis, James W. Foulk, Kevin A. Nibur & Dorian K. Balch

* DOI: 10.1007/s11837-014-1050-8

* Publication Date: August 2014