A continuum model for hydrogen-assisted void nucleation in ductile materials

The bulk effects of hydrogen on the kinematics, thermodynamics, and kinetics of plasticity and damage evolution were derived based on the constitutive equations of the Bammann continuum plasticity and Horstemeyer damage mechanics framework. From nanoscale atomistic simulation results and existing experimental observations, the Horstemeyer–Gokhale void/crack nucleation rate was modified to account for hydrogen effects. The continuum damage framework was implemented into a user material code and applied in finite element simulations. The finite element results showed close comparisons with the experimental data from Kwon and Asaro who charged smooth and notched spheroidized 1518 steel specimens with hydrogen. (paper)