Abstract

This paper presents a cohesive zone model of fracture in Cu and Ni single crystals under tension, based on an atomistic analysis. The molecular-statics approach based on the conjugate-gradient method was used to investigate the crack-growth behavior at the atomic level. The fracture toughness was evaluated on the basis of energy considerations, and the cohesive traction was calculated using the J integral and the atomic-scale separation in the cohesive zone. The cohesive traction and separation curves obtained using computational data from atomistic simulations were compared with the exponential form of continuum mechanics. The results showed that the exponential form satisfactorily represented the cohesive zone properties of Cu. However, the cohesive traction and separation curves for Ni were found to deviate from the exponential form in the softening stage, owing to small-scale nonlinear features near the cohesive zone.

Graphic Abstract

中文翻译：

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基于原子模拟的FCC单晶裂纹扩展的内聚区建模

摘要

基于原子分析，本文提出了Cu和Ni单晶在拉伸下的断裂的内聚区模型。采用基于共轭梯度法的分子静态方法研究了原子级的裂纹扩展行为。基于能量考虑因素评估断裂韧性，并使用J计算内聚力。积分和原子尺度分离的内聚区。使用来自原子模拟的计算数据获得的内聚牵引力和分离曲线与连续力学的指数形式进行了比较。结果表明，指数形式令人满意地表示了Cu的内聚区性质。然而，由于内聚区附近的小尺度非线性特征，在软化阶段发现Ni的内聚牵引力和分离曲线偏离指数形式。

图形摘要