The strength of diamond under uniaxial loading has been widely studied, but little attention has been paid to its strength under complex loadings. In this study, we investigate the theoretical strength under complex loadings based on a nonequilibrium energy model. Two atomistic modeling approaches based on the empirical potential model and density functional theory are applied. Using these two approaches, we derived the strength, strength contours, and strength surfaces under uniaxial, biaxial, and triaxial loadings along the <100> direction. The results are in good agreement with the results of some previous studies, and they show that diamond has a strong tension–compression strength asymmetry effect.

金刚石在单轴载荷下的强度已经得到了广泛的研究，但是对于复杂载荷下的强度却鲜有关注。在这项研究中，我们研究了基于非平衡能量模型的复杂载荷下的理论强度。运用了两种基于经验势模型和密度泛函理论的原子建模方法。使用这两种方法，我们得出了沿<100>方向在单轴，双轴和三轴载荷下的强度，强度轮廓和强度表面。结果与先前的一些研究结果非常吻合，它们表明金刚石具有很强的抗拉强度和抗压强度不对称作用。