在辐射材料中塑料流量定位的多尺度建模
de la Rubia TD1, Zbib, Khraishi
1Lawrence Livermore National Laboratory, Livermore, California 94550, USA. delarubia@llnl.gov
Nature
|September 6, 2000
概括
能量粒子辐射会降解金属,导致塑料流的局部化. 多尺度模拟显示缺陷集群引脚位移,导致解引脚和交叉滑动,最终限制塑料通道宽度.
科学领域:
- 材料科学 材料科学 材料科学
- 核工程 核工程是指核工程.
- 计算物理 计算物理
背景情况:
- 能量粒子辐射显著降低金属的机械性能,包括增加产应力和降低性.
- 这些影响对核电站压力容器和核聚变能源材料至关重要,但基本机制尚不清楚.
- 塑料流量定位是辐射的关键后果,影响材料性能和寿命.
研究的目的:
- 阐明塑料流在辐射金属中的本地化基本机制.
- 为了证明辐射场与观察到的机械性能降解之间的关系.
- 揭示塑料流域定位在被辐射金属内的无缺陷通道中的过程.
主要方法:
- 使用了三维多尺度模拟.
- 模拟了受辐射的金属在压力下的行为.
- 研究了脱位动态和与辐射诱导缺陷的相互作用.
主要成果:
- 通过辐射诱导的缺陷集群观察到的脱位固定.
- 通过缺陷吸收证明了随后的脱位解.
- 鉴定出异位的交叉滑动作为一个依赖应力机制.
- 发现塑料流通道宽度受到脱位二极体和缺陷集群之间的相互作用的限制.
结论:
- 这项研究揭示了塑料流在被辐射的金属中定位的详细机制.
- 脱位动态和缺陷相互作用是理解辐射诱导的机械性质变化的关键.
- 模拟结果为辐射下的材料行为提供了基本的见解,这对于核和核聚变应用至关重要.
相关概念视频
Plastic Deformations
532
It is essential to understand how structural members behave under plastic deformation when the bending stress exceeds the material's yield strength. This state of deformation permanently alters the shape of the member, in contrast to the linear elastic behavior observed before yielding. The strain at any point in the member is expressed in terms of maximum strain. Notably, the neutral axis, which coincides with the centroid during elastic bending, shifts away from the centroid under plastic...
532
Plastic Deformations of Members with a Single Plane of Symmetry
415
When a structural member undergoes plastic deformation due to bending, it is crucial to understand the position of the neutral axis and the stress distribution. This member, characterized by a single plane of symmetry, exhibits a uniform stress distribution, with negative stress above the neutral axis and positive stress below. Notably, the neutral axis does not align with the centroid of the cross-section. This misalignment is typical in cases where the cross-section is not rectangular or...
415
Plastic Behavior
639
A material's elastic behavior is characterized by the disappearance of stress once the load is removed, allowing the material to return to its original state. However, when stress surpasses the yield point, yielding commences, marking the onset of plastic deformation or permanent set. This change from elastic to plastic behavior is influenced by the peak stress value and the duration before the load is removed. An intriguing observation occurs when a specimen is loaded, unloaded, and...
639
Typical Model Studies
660
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
660


