在缓慢的三维断裂中拓缺陷形成
Yuri Lubomirsky1, Eran Bouchbinder1
1Chemical and Biological Physics Department, <a href="https://ror.org/0316ej306">Weizmann Institute of Science</a>, Rehovot 7610001, Israel.
Physical review letters
|December 13, 2024
概括
3D材料中的裂纹表面步骤是由于灭的混乱和混合模式加载而产生的. 这项研究揭示了这些因素在骨折期间的阶段形成中的相互作用.
科学领域:
- 材料科学 材料科学 材料科学
- 固体力学 固体力学是什么
- 断裂力学 断裂力学 断裂力学
背景情况:
- 三维材料的裂显示出复杂的表面图案.
- 突破对称的拓缺陷,如表面步骤,在缓慢加载下出现拉力 (模式-I) 断裂.
- 之前的研究揭示了动态拉伸断裂,但没有揭示阶段形成机制.
研究的目的:
- 研究3D材料中裂纹表面阶段形成的潜在物理机制.
- 为了证明相场框架可以重现裂表面的步骤.
- 识别关键的物理成分和它们在步骤形成中的相互作用.
主要方法:
- 利用相场框架在3D中模拟裂传播.
- 将有限强度的灭混乱纳入材料模型.
- 在主导拉力 (模式-I) 负载的同时,引入了一个小型的,半透视的反平面剪切 (模式-III) 负载组件.
主要成果:
- 阶段场模型成功地重现了裂纹表面的阶段形成.
- 阶段形成需要灭的障碍和混合模式I + III加载.
- 量化了调节阶段形成中的失调 (强度,相关长度) 和模式I+III混合之间的非线性关系.
- 观察到表面步骤从背景粗开始,由重叠的裂段组成,由桥梁连接在一起.
结论:
- 裂纹表面的阶段形成是由物质混乱和混合模式负载的联合作用决定的.
- 阶段场方法为研究复杂的断裂现象提供了一个强大的框架.
- 这些发现与裂表面形态的实验观测一致.
相关概念视频
Fractures: Bone Repair
2.9K
Treatment for a fracture is based on the type of break, the bone affected, and the patient's age.
Minor fractures with no bone displacement are treated by immobilizing the fractured bone using a cast or splint. However, in the case of fractures with displaced bones, the broken bones are repositioned before immobilization to ensure successful healing without deformation and loss of function. The realignment of fractured bone ends is performed through a process called reduction. If the...
Minor fractures with no bone displacement are treated by immobilizing the fractured bone using a cast or splint. However, in the case of fractures with displaced bones, the broken bones are repositioned before immobilization to ensure successful healing without deformation and loss of function. The realignment of fractured bone ends is performed through a process called reduction. If the...
2.9K
Thin-Walled Hollow Shafts
167
In analyzing a thin-walled hollow shaft subjected to torsional loading, a segment with width dx is isolated for examination. Despite its equilibrium state, this segment faces torsional shearing forces at its ends. These forces are quantitatively described by the product of the longitudinal shearing stress on the segment's minor surface and the area of this surface, leading to the concept of shear flow. This shear flow is consistent throughout the structure, indicating a uniform distribution...
167
Deformations in a Symmetric Member in Bending
161
When analyzing the deformation of a symmetric prismatic member subjected to bending by equal and opposite couples, it becomes clear that as the member bends, the originally straight lines on its wider faces curve into circular arcs, with a constant radius centered at a point known as Point C. This phenomenon helps to understand the stress and strain distribution within the member more clearly.
When the member is segmented into tiny cubic elements, it is observed that the primary stress...
When the member is segmented into tiny cubic elements, it is observed that the primary stress...
161
Three-Dimensional Analysis of Strain
203
Three-dimensional strain analysis is crucial for understanding how materials deform under stress, particularly in elastic, homogeneous materials. This method employs principal stress axes to simplify complex stress states into more understandable forms. Subjected to stress, a small cubic element within a material either expands or contracts along these axes, transforming into a rectangular parallelepiped. This transformation effectively illustrates the material's deformation. The principal...
203
Deformations in a Transverse Cross Section
172
When a material is subjected to uniaxial stress, it elongates or contracts in the direction of the applied force, and also undergoes changes in the perpendicular directions. This behavior is crucial for understanding how materials behave under stress and is governed by mechanical properties such as Poisson's ratio v, which measures the ratio of transverse strain to axial strain.
As the material stretches, it expands or contracts in orthogonal directions to the load. This phenomenon varies...
As the material stretches, it expands or contracts in orthogonal directions to the load. This phenomenon varies...
172


