Constant intermittent flow of dislocations: central problems in plasticity
Constant intermittent flow of dislocations: central problems in plasticity
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DOI：
10.1179/174328412x13409726212768
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发表时间：
2012-11-01
影响因子：
1.8
通讯作者：
Brown, L. M.
中科院分区：
文献类型：
--
作者：
Brown, L. M.
无论在时间上还是在空间上，塑料流动都不是一个连续的过程，但它仍然以这种方式建模。本文从自组织临界性（SOC）的角度对塑性进行了讨论。讨论了以下主题：滑移带及其模型;滑移是如何结晶的？位错的分布源和集体运动;泰勒模型的成功和失败;长程应力并不直接影响流动应力，所以森林法则;粗晶化的危险和平滑的工程变量与间歇波动的物理变量之间的关系;滑移带的加工硬化;什么控制滑移带的结构？前兆和耗尽阶段的解释;与其他最近的理论的关系;从一个健全的塑性流动理论得出的结论。简短的附录提出的代数结果为模型的椭球体的滑移带。
Plastic flow is never a continuous process either in time or in space, yet it continues to be modelled in this way. In this review, plasticity is discussed from the perspective of self-organised criticality (SOC). The following topics are discussed: slip bands and models for them; how crystallographic is slip?; distributed sources and collective motion of dislocations; the triumph and the failure of the Taylor model; long range stress does not contribute directly to the flow stress, so the forest rules; the perils of coarse-graining and the relationship between smoothed engineering variables and intermittently fluctuating physical variables; work-hardening of a slip band; what controls the structure of slip bands?; interpretation of precursor and exhaustion phases; relationship to other recent theories; consequences which follow from a sound theory of plastic flow. Brief appendices present algebraic results for slip bands modelled as ellipsoids.