Crack growth prediction and cohesive zone modeling of single crystal aluminum-a molecular dynamics study

VK Sutrakar and N Subramanya and DR Mahapatra, ADVANCES IN NANO RESEARCH, 3, 143-168 (2015).

DOI: 10.12989/anr.2015.3.3.143

Initiation of crack and its growth simulation requires accurate model of traction - separation law. Accurate modeling of traction-separation law remains always a great challenge. Atomistic simulations based prediction has great potential in arriving at accurate traction-separation law. The present paper is aimed at establishing a method to address the above problem. A method for traction-separation law prediction via utilizing atomistic simulations data has been proposed. In this direction, firstly, a simpler approach of common neighbor analysis (CNA) for the prediction of crack growth has been proposed and results have been compared with previously used approach of threshold potential energy. Next, a scheme for prediction of crack speed has been demonstrated based on the stable crack growth criteria. Also, an algorithm has been proposed that utilizes a variable relaxation time period for the computation of crack growth, accurate stress behavior, and traction- separation atomistic law. An understanding has been established for the generation of smoother traction-separation law (including the effect of free surface) from a huge amount of raw atomistic data. A new curve fit has also been proposed for predicting traction-separation data generated from the molecular dynamics simulations. The proposed traction- separation law has also been compared with the polynomial and exponential model used earlier for the prediction of traction-separation law for the bulk materials.

Return to Publications page