Simulation of hydrogen embrittlement of steel using mixed nonlocal finite elements

A new simulation strategy to model hydrogen embrittlement based on a multi-field finite element using displacements, pressure, volume variation, nonlocal damage variables and lattice concentration as unknowns is proposed. The material described modified GTN model, which includes the description of enhanced decohesion (HEDE). problem solved fully implicit formulation. Numerical problems related volumetric locking are mixed pressure/volume variation use formulation allows straightforward evaluation pressure gradient, drives diffusion. Mesh size dependence an gradient Two used represent damage: plastic accumulated strain, controlling nucleation. simulate existing experimental database (Moro et al., 2010; Briottet 2012) including tensile, fracture toughness pressurized disk tests. after adjusting various coefficients, can main findings: effect deformation rate failure tensile specimens, transition from surface internal with increasing rate, sharp drop under (CT specimen), location pressurization in case tests disks.