在拉伸预负荷和冲击负荷组合下,CFRP层板的分层行为
Kaiwei Lan1, Haodong Wang1, Cunxian Wang1,2,3
1School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China.
Materials (Basel, Switzerland)
|October 14, 2023
概括
双轴拉伸预负荷在高速冲击时减少了碳纤维增强聚合物 (CFRP) 层面中的分层,特别是在中心. 然而,接近边缘的冲击可能会在预加载下增加分层.
科学领域:
- 材料科学 材料科学 材料科学
- 机械工程 机械工程
- 航空航天工程 航空航天工程
背景情况:
- 飞机复合结构在撞击事件中经常经历预加载条件.
- 了解撞击下的分层行为对于结构完整性和安全性至关重要.
研究的目的:
- 为了研究双轴在平面内拉力预负荷对CFRP层材在高速冲击时的分层的影响.
- 分析预装载,冲击速度和位置对分层的影响.
- 用数值模拟来验证实验发现.
主要方法:
- 使用高速气炮系统进行弹道测试.
- 在不同速度 (50-90 m/s) 的中部和近边缘撞击地点进行了调查.
- 使用ABAQUS/Explicit与VUMAT子程序和修改的Hou标准进行数值模拟.
主要成果:
- 在冲击中心时,双轴拉力预负荷将分层面积减少了14.236.7%.
- 接近边缘的影响显示出不同的结果,一些病例呈现出增加的分层 (高达19.3%的下降).
- 实验和模拟结果显示良好一致,最大误差为12.9%.
结论:
- 前载值和冲击速度显著影响CFRP层材的分层行为.
- 双轴拉伸预负荷增强了对外平面移位的抵抗力,但可以降低层接口的刚性.
- 复杂的分层行为是由竞争的应力强化和接口刚性降解效应解释的.
相关概念视频
Plastic Behavior
213
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...
213
Residual Stresses in Bending
181
In the study of elastoplastic members subjected to bending moments, understanding the loading and unloading phases is crucial for assessing material behavior and structural integrity. During the loading phase, as the bending moment increases, the material initially responds elastically, adhering to Hooke's Law, where stress is directly proportional to strain. When the load exceeds the yield strength, plastic deformation occurs, resulting in permanent strain and deformation that remains even...
181
Plastic Deformations
135
Plastic deformation represents a fundamental concept in materials science, which explains the irreversible change in the shape of a material when it experiences stress beyond its elastic capability. This phenomenon is important in structural engineering, especially in designing and analyzing cantilever beams—structures that are securely fixed at one end and bear loads at the opposite end. When these beams are subjected to loads within their elastic range, they will return to their...
135
Behavior of Concrete Under Compressive Load
184
Concrete exhibits specific behaviors under different compressive loads. Understanding this is crucial for understanding its structural integrity. When concrete undergoes uniaxial compression, it tends to develop cracks that run parallel to the direction of the force. These parallel cracks stem from localized tensile stresses that occur perpendicular to the compression direction. Additionally, angled cracks may appear due to the formation of shear planes.
As the concrete specimen fractures under...
As the concrete specimen fractures under...
184
Fatigue
189
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...
189
Stress-Strain Diagram - Ductile Materials
794
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...
794


