标题： 位错网络在应变强化过程中的链接统计 显示英文标题

标题： Link Statistics of Dislocation Network during Strain Hardening

摘要： 位错是晶体中的线缺陷，在应变硬化过程中会增殖并自组织成复杂的网络。连接该网络中相邻节点的位错链的长度包含了关于演变的位错微结构的关键信息。通过分析面心立方(fcc)铜的离散位错动力学(DDD)模拟数据，我们表征了在单个滑移系统上应变硬化期间位错网络的链长统计分布。我们的分析显示，活性滑移系统上的链长遵循双指数分布，而非活性滑移系统上的链长符合单指数分布。双指数分布中观察到的显著长尾是由于在活性滑移系统上长链的应力诱导弯曲，这一特征在去除施加的应力后消失。我们进一步证明，两种观察到的链长分布可以通过将一维泊松过程扩展为包含不同的生长函数来解释。具体而言，当超过临界长度的链的生长速率变为超线性时，就会出现双指数分布，这与长链在应力下弯曲的物理现象一致。这项工作加深了我们对应变硬化过程中位错微结构演化的理解，并阐明了其形成的潜在物理机制。 显示英文摘要

摘要： Dislocations are line defects in crystals that multiply and self-organize into a complex network during strain hardening. The length of dislocation links, connecting neighboring nodes within this network, contains crucial information about the evolving dislocation microstructure. By analyzing data from Discrete Dislocation Dynamics (DDD) simulations in face-centered cubic (fcc) Cu, we characterize the statistical distribution of link lengths of dislocation networks during strain hardening on individual slip systems. Our analysis reveals that link lengths on active slip systems follow a double-exponential distribution, while those on inactive slip systems conform to a single-exponential distribution. The distinctive long tail observed in the double-exponential distribution is attributed to the stress-induced bowing out of long links on active slip systems, a feature that disappears upon removal of the applied stress. We further demonstrate that both observed link length distributions can be explained by extending a one-dimensional Poisson process to include different growth functions. Specifically, the double-exponential distribution emerges when the growth rate for links exceeding a critical length becomes super-linear, which aligns with the physical phenomenon of long links bowing out under stress. This work advances our understanding of dislocation microstructure evolution during strain hardening and elucidates the underlying physical mechanisms governing its formation.