A study of the loading path and crystal orientation effects on size-dependent limit strength

To better understand the loading path and crystal orientation effects on size-dependent material strength, molecular dynamics (MD) simulations are performed with the use of single crystal diamond (SCD) of various sizes under uniaxial tension and simple shear loading conditions. In the MD simulations, mechanical responses of SCD blocks with three different sizes under 〈1 0 0〉 and 〈1 1 0〉 tensions, and under {1 0 0}〈0 1 0〉, {1 0 0}〈1 1 0〉 and {1 1 0}〈0 0 1〉 shear slips at different loading rates are studied. Based on the simulation data, a power scaling law is proposed to predict the size effect on the material strength of pristine diamond under given loading conditions.