粘合结构的拉伸失效行为基于现场X射线CT和FEA
Jiawen Tang1, Bo Niu1,2, Yu Cao1
1State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.
Materials (Basel, Switzerland)
|December 23, 2023
概括
粘合键中的孔隙缺陷通过引起应力度来削弱结构. 较大的毛孔,无论形状如何,都会引发裂并导致故障,影响粘合性能.
科学领域:
- 材料科学 材料科学 材料科学
- 机械工程 机械工程
- 非破坏性测试 不破坏性测试
背景情况:
- 粘合剂粘合对于结构完整性至关重要.
- 粘合剂层内的孔隙缺陷显著降低了粘合强度.
- 毛孔的内部性质使得它们对故障机制的影响难以研究.
研究的目的:
- 研究具有孔隙缺陷的粘合粘合结构中的实时微故障机制.
- 了解孔隙特征对拉伸性故障行为的影响.
- 为了将毛孔大小和形状与应力度和裂传播相关联.
主要方法:
- 在现场进行X射线微型计算机断层扫描 (微型CT) 以实时观察微型故障.
- 高精度有限元分析 (FEA) 用于应力分布分析.
- 基于微型CT数据的粘合层模型的开发.
主要成果:
- 在拉伸负荷时,孔隙会在粘合层中诱导显著的应力度.
- 压力度水平主要取决于毛孔大小,而不是形状.
- 较大的孔隙作为裂的启动点,导致结构失灵.
结论:
- 孔径大小是决定缺陷对粘合剂粘合强度的有害影响的关键因素.
- 这项研究更深入地了解了粘合剂粘合中的毛孔缺陷机制.
- 研究结果为改善粘合结构的设计和可靠性提供了洞察力.
相关概念视频
Yield Criteria for Ductile Materials under Plane Stress
164
In designing structural elements and machine parts using ductile materials, it is crucial to ensure that these components withstand applied stresses without yielding. Yielding is initially determined through a tensile test, which evaluates the material's response to uniaxial stress. However, tensile stress is insufficient when components face biaxial or plane stress conditions This condition requires advanced criteria to predict failure.
The Maximum Shearing Stress Criterion, also known as...
The Maximum Shearing Stress Criterion, also known as...
164
Fatigue
185
Fatigue occurs when materials rupture under repeated or fluctuating loads, even at stress levels far below their static breaking strength. It typically results in brittle failure, even for ductile materials. It is a critical consideration in designing machines and structural components subjected to repetitive or varying loads. The nature of these loadings can range from fluctuating loads like unbalanced pump impellers causing vibrations to repeatedly bending a thin steel rod wire back and forth...
185
Tensile Strength Considerations of Concrete
132
Considering the tensile strength of concrete involves recognizing that the theoretical strength of cement paste can be up to a thousand times higher than what is observed in practical applications. This significant discrepancy is largely attributed to the presence of microscopic cracks within the concrete. These cracks tend to amplify stress at their tips when a load is applied, a phenomenon explained by Griffith's theory of brittle fracture.
The dimensions and shape of a concrete specimen...
The dimensions and shape of a concrete specimen...
132
Mechanical Characteristics of Steel
578
The mechanical characteristics of steel are assessed through various tests that evaluate its strength, toughness, and flexibility. These tests include tension, torsion, impact, bending, and hardness assessments, each providing crucial information about steel's suitability for specific applications.
The tension test is fundamental for determining tensile strength. In this test, a steel specimen is stretched using a gripping device until it breaks. The data collected during this test are used...
The tension test is fundamental for determining tensile strength. In this test, a steel specimen is stretched using a gripping device until it breaks. The data collected during this test are used...
578
Stress-Strain Diagram - Brittle Materials
2.4K
Brittle materials, including glass, cast iron, and stone, exhibit unique characteristics. They fracture without considerable change in their elongation rate, indicating that their breaking and ultimate strength are equivalent. Such materials also show lower strain levels at the point of rupture. The failure in brittle materials predominantly results from normal stresses, as evidenced by the rupture created along a surface perpendicular to the applied load. These materials do not display...
2.4K
Stress-Strain Diagram - Ductile Materials
728
The stress-strain relationship in ductile materials such as structural steel or aluminium is intricate and progresses through several stages. When a specimen is loaded, it initially exhibits a linear length increase, depicted by a steep straight line on the stress-strain diagram. It indicates the material is elastically deforming and will return to its original shape once unloaded. However, when a critical stress value is reached, plastic deformation begins. This stage sees substantial...
728


