Petr Hora

Crack Orientation versus Ductile-Brittle Behavior in 3D Atomistic Simulations

The paper presents results of molecular dynamic (MD) simulations in 3D bcc iron crystals with edge pre-existing cracks (001)[110] and (110) [110] (crack plane/crack front) loaded uni-axially in tension mode I at temperature of 300 K. The iron crystals in MD have the same orientation and similar geometry as in our recent fracture tests performed at room temperature on iron (3wt.%Si) single crystals [1].

Ductile-Brittle Behavior of Microcracks in 3D

Results of several parallel molecular dynamics crack simulations in bcc iron crystals with up to 128 million atoms are presented. The crack (001)[010] of Griffith type is loaded in Mode I. We observe dislocation emission and twinning near the free sample surfaces and later plastically induced crack initiation.

Sample Geometry and the Brittle-Ductile Behavior of Edge Cracks in 3D Atomistic Simulations by Molecular Dynamics

We present new results of molecular dynamic (MD) simulations in 3D bcc iron crystals with edge cracks (001)[010] and (-110)[110] loaded in mode I. Different sample geometries of SEN type were tested with negative and positive values of T-stress according to continuum prediction by Fett.

Ductile-Brittle Behavior along Crack Front and T-Stress

We present new results of molecular dynamic (MD) simulations in 3D bcc iron crystals with embedded central through crack (001)[110] of Griffith type loaded in mode I. Two different sample geometries of the same crystallographic orientation were tested with negative and positive values of the T-stress, which change the ductile-brittle behavior along the crack front in 3D. This phenomenon is explained in the framework of stress analysis, both on the continuum and atomistic level.