在激光冲击处理中,粘性拖对在高产强度材料中可实现的最大残余应力的影响
Ignacio Angulo1, Wsewolod Warzanskyj1, Francisco Cordovilla1
1UPM Laser Centre, Polytechnical University of Madrid, C/Alan Turing 1, 28031 Madrid, Spain.
Materials (Basel, Switzerland)
|November 14, 2023
概括
激光冲击处理 (LSP) 模拟需要精确的材料模型. 这项研究结合了高拉伸率效应,挑战了传统模型,并揭示了压力衰变对合金中的塑料拉伸的影响.
科学领域:
- 材料科学 材料科学 材料科学
- 机械工程 机械工程
- 计算建模 计算建模
背景情况:
- 激光冲击处理 (LSP) 是一种用于增强材料性能的表面处理方法.
- 传统的LSP模拟通常使用高应变速率变形模型,这些模型可能无法准确地代表极端应变速率的材料行为.
- 准确的建模对于预测和优化诱导的余应力和材料响应至关重要.
研究的目的:
- 在超出10^4 s^-1 (粘性状态) 的延展率下,在LSP模拟中明确纳入实验观察到的产量应力增加.
- 挑战LSP模拟中使用的传统接受的延展率范围.
- 调查压力衰减对LSP过程中获得的塑料总应变的影响.
主要方法:
- 详细审查与LSP条件相关的常见高应变率变形模型.
- 为合金开发一种材料模型,该模型明确包括突如其来的应力增加超过10^4s^-1.
- 一种结合数值分析的方法来预测塑料菌株的时间演变.
- 使用扩展区域辐射 (25x25 mm^2) 和用于残余应力分析的孔钻方法进行数值实验验证.
- 在模拟中包括近地表温度梯度.
主要成果:
- 传统的高应变率硬化模型 (例如,约翰逊-库克) 在LSP模拟中高估了诱导的压力余应力.
- 包括粘性体制 (延展率> 10^4 s^-1) 显著改变了预测的材料反应.
- 压力衰变,经常被忽视,在LSP处理过程中获得的总塑料应变中起着重要作用.
- 该研究挑战了当前LSP模拟中假定的典型延展率范围 (10^6-10^7 s^-1).
结论:
- 在LSP模拟中使用的标准材料模型可能会导致对残余应力的不准确预测,因为忽视了高应变率材料的行为.
- 精确的材料建模,包括粘度状态和压力衰变,对于可靠的LSP模拟至关重要.
- 对于先进的LSP应用,需要进一步研究极端应变速率下的材料行为.
更多相关视频
10:52Conducting Elevated Temperature Normal and Combined Pressure-Shear Plate Impact Experiments Via a Breech-end Sabot Heater System
Published on: August 7, 2018
8.6K
08:40Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing
Published on: February 11, 2016
11.7K
相关概念视频
01:26Residual Stresses
224
Residual stresses reside in a structure even after removing the original stress inducer. This phenomenon often arises from varied plastic deformations across different parts of a structure. Consider a rod stretched beyond its yield point. It will not regain its original length due to permanent deformation. Even after load removal, the rod does not entirely lose stress because of uneven plastic deformations, resulting in residual stresses. The computation of these stresses in structures is...
224
01:10Residual Stresses in Circular Shafts
179
In materials that exhibit elastic and plastic behavior, known as elastoplastic materials, residual stresses can accumulate when these materials experience plastic deformation. This deformation arises from either high levels of shearing stress or significant strains. Residual stresses are internal stresses that persist within a material after removing the external force causing deformation. This phenomenon is demonstrated when observing the behavior of a shaft under torque; notably, the...
179
01:21Plastic Behavior
200
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...
200
01:25Yield Criteria for Ductile Materials under Plane Stress
166
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...
166
01:19Impact Loading
204
Impact loading occurs when a moving object collides with a stationary structure, such as a rod with a uniform cross-sectional area fixed at one end. Under these conditions, the rod absorbs the kinetic energy from the striking object, leading to deformation and subsequent stress development. As the rod returns to its original position and reaches maximum stress, the absorbed energy, initially manifested as kinetic energy, transforms entirely into strain energy.
In cases of elastic deformation,...
In cases of elastic deformation,...
204
01:18Residual Stresses in Bending
178
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...
178