Atomistic simulation of the bending deformation of a single-crystalline nano-beam

Bending of a single-crystalline simply supported nano-beam is simulated with a molecular dynamics method. By changing the value of the span, the width and the depth of the cross section, and by varying the uniformly distributed load from 3.47 □10-4 to 11.6GPa, the results show that the span, the width, the depth and the uniformly distributed load all have effect on the vertical displacement (deflection) of the beam. When the load is beyond 0.0347GPa, the deflection increases and the deflection curve gets smoother as the load and the MD time step. When the load is less than 0.0347 GPa, the deflection has apparently no change with the increase of the load and the MD time step. The MD time step has little any effect on the horizontal displacement (along the width of the beam). The horizontal displacement decrease as the load increases. The span of the beam has little effect on the maximal deflection of the beam. The deflection decreases as the depth and width of the beam increasing. As the ratio of the surface area to the volume of the beam is decreasing, the deflection curve gets smoother with the exception of the depth whose value equates to 12a or 14a (a represents the lattice constant). When the ratio of the deflection to the horizontal displacement is beyond one unit, the uniformly distributed load plays a significant part in the bending deformation. However when the ration is within a unit, the horizontal deformation must be taken into account, which sometimes makes itself into a great deformation.