0000000000930923
AUTHOR
Pekka Heino
Molecular Dynamics Study of Copper and Aluminum under Mechanical Strain
AbstractMechanical properties of copper and aluminum have been studied using finite temperature molecular dynamics simulations. Atomic interactions have been described by a many-atom effective medium potential, which takes into account interactions up to third neighbors. The computed elastic constants showed good agreement with experimental data. Encouraged by these results the model was applied to study fracture in copper. Systems with a grain boundary and an initial cut serving as a crack seed have been studied. In the first case, crack nucleation and propagation took place exclusively at the grain boundary. In the second case, dislocation propagation was observed in one of the <110>…
Molecular-dynamics study of mechanical properties of copper
Mechanical properties of copper have been studied using effective-medium theory and Molecular-Dynamics simulations. At room temperature we calculate the tensile moduli of systems that are elongated along different crystal orientations. These moduli are in very good agreement with the experimental values, the difference being less than 6%. The elastic constants obtained from simulations were also in good agreement with experiments. In addition, the point of maximum stress is found to be of the same order of magnitude as the experimental value. Also crack propagation in systems with periodic boundaries has been studied and micro-voids are seen to generate near the crack tip. Crack propagation…
Molecular-dynamics study of copper with defects under strain
Mechanical properties of copper with various types of defects have been studied with the molecular-dynamics method and the effective-medium theory potential both at room temperature and near zero temperature. The loading has been introduced as constant rate straining and the dynamics of the process region of fracture is purely Newtonian. With the model three types of defects were studied: point defects, grain boundary, and an initial void serving as a crack seed. Point defects were seen to decrease the system strength in terms of fracture stress, fracture strain, and elastic modulus. Due to random microstructure, highly disordered systems turned out to be isotropic, which on the other hand …