Abstract

This paper discusses a subcritical crack nucleation mechanism in a brittle solid within a real range of applied stress. A medium deformed by uniaxial tension is considered as an open nonequilibrium system of nuclei and electrons. Structural relaxation of the medium begins with the excitation of dynamic displacements during nonadiabatic Landau–Zener transitions. Dynamic displacements induce the instability of the medium to the longitudinal displacement wave. The kinetics of structural relaxation is described by two nonlinear parabolic kinetic equations for dynamic order parameters. Conditions are derived for the existence of localized solutions (autosolitons). The excitation of autosolitons leads to local elongation and cross-sectional reduction of the specimen. The resulting neck is a subcritical crack.

中文翻译：

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固体中非绝热驱动的亚临界裂纹形核

摘要

本文讨论了实际施加应力范围内脆性固体中的亚临界裂纹成核机制。由单轴张力变形的介质被认为是由原子核和电子组成的开放非平衡系统。介质的结构弛豫始于非绝热朗道-齐纳跃迁期间动态位移的激发。动态位移引起介质对纵向位移波的不稳定性。结构弛豫动力学由动态阶参数的两个非线性抛物线动力学方程描述。导出局部解（自孤子）存在的条件。自孤子的激发导致样本的局部伸长和横截面减小。由此产生的颈部是亚临界裂纹。