Crack Length Effect on the Fracture Behavior of Single-Crystals and Bi-Crystals of Aluminum

Abstract

Molecular dynamics simulations of cracked nanocrystals of aluminum were performed in order to investigate the crack length and grain boundary effects. Atomistic models of single-crystals and bi-crystals were built considering 11 different crack lengths. Novel approaches based on fracture mechanics concepts were proposed to predict the crack length effect on single-crystals and bi-crystals. The results showed that the effect of the grain boundary on the fracture resistance was beneficial increasing the fracture toughness almost four times for bi-crystals.

Fatigue Life Estimation Model of Repaired Components with the Expanded Stop-Hole Technique

“…Thus, a fatigue crack growth model is required to obtain accurate life predictions. Fracture mechanics-based models have been properly used for crack propagation analysis and prediction of mechanical behavior [33][34][35][36][37][38][39][40][41][42].…”

Mechanisms during Strain Rate-Dependent Crack Propagation of Copper Nanowires Containing Edge Cracks

“…As the crack length increases, the Young’s modulus decreases. Velilla-Díaz et al [ 19 ] performed molecular dynamics simulations on aluminum nanocrystals. Atomic models of single and bicrystals were developed considering eleven different crack lengths.…”

Effects of Grain Boundary Misorientation Angle on the Mechanical Behavior of Al Bicrystals

“…Tensile and fatigue resistance of metallic materials greatly depends on grain size and the effect of the misorientation angle on the propagation of tiny and sharp defects [1][2][3][4][5][6][7]. In order to improve mechanical and fatigue properties, the interaction between defects and GB has to be investigated.…”

“…In order to improve mechanical and fatigue properties, the interaction between defects and GB has to be investigated. Previous experimental and computational investigations have established that the GB works as a barrier that blunts the tip and arrests the propagation of small cracks [3,6,7]. In nanocrystals of aluminum (Al), the volume fraction of GBs significantly affects the mechanical response of the material [8].…”

“…In nanocrystals of aluminum (Al), the volume fraction of GBs significantly affects the mechanical response of the material [8]. Single crystals normally show brittle behavior, whereas bicrystals tend to be ductile due to the presence of the GB [6,7]. On the other hand, considering that the relative grain misorientation angle plays an important role in the tensile and crack propagation resistances of crystalline materials [5][6][7][9][10][11][12][13][14], the effect of this angle is another factor that has to be deeply studied for a better understanding of some failure mechanics that occur in metallic materials, such as ductile, brittle and fatigue failure.…”