A novel multiscale approach to brittle fracture of nano/micro‐sized components. Issue 8 (29th December 2019)

• Record Type: Journal Article
• Authors: Kotoul, Michal; Skalka, Petr; Profant, Tomáš; Řehák, Petr; Šesták, Petr; Černý, Miroslav; Pokluda, Jaroslav
• Other Names: Vormwald Michael guestEditor.; Hong Youshi guestEditor.; James Neil guestEditor.; Susmel Luca guestEditor.; Iacoviello Francesco guestEditor.
• Is Part Of: Fatigue & fracture of engineering materials & structures. Volume 43:Issue 8(2020)
• Page Start: 1630
• Page End: 1645
• Publication Date: 2019-12-29
• Subjects: DFT -- FEM -- fracture nanomechanics -- size‐dependent phenomena -- strain gradient elasticity; Materials -- Fatigue -- Periodicals; Fracture mechanics -- Periodicals; 620.1123
• DOI: 10.1111/ffe.13179
• Languages: English
• ISSNs: 8756-758X

Abstract

Abstract: Principles and advantages of a new concept based on the ab initio aided strain gradient elasticity theory are shown in comparison with the classical Barenblatt cohesive model. The method is applied to the theoretical prediction of the critical energy release rate and the crack tip opening displacement at the crack instability in nanopanels made of germanium and molybdenum crystals. The necessary length scale parameter l 1 is determined for germanium and molybdenum by the best gradient elasticity fits of ab initio computed screw dislocation displacements and phonon dispersions. Values of ab initio computed critical energy release rates and crack opening profiles revealed that the length l 1 is related to inflexion points of profiles. A novel ab initio method in combination with continuum mechanics was successfully tested to replace molecular statics dependent of availability of interatomic potentials. The asymptotic strain gradient elasticity solution for displacement components near the crack tip in materials with cubic lattice was also derived.