通过激光诱导的振动信号对元材料进行动态诊断
Yun Kai1,2, Somayajulu Dhulipala1, Rachel Sun1
1Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
Nature
|November 16, 2023
概括
研究人员开发了一种新的非接触方法来研究微尺度机械超材料的动态性质. 这种框架可用于高级材料发现的硬度,阻尼和缺陷的高通量表征.
科学领域:
- 材料科学
- 机械工程
- 纳米技术
背景情况:
- 微型机械超材料具有独特的静态性质,但它们的动态行为不太了解.
- 现有的动态属性的特征化方法往往是低吞吐量,破坏性或缺乏确定的协议.
- 动态特性对于抗冲击,声波导和振动阻尼等应用至关重要.
研究的目的:
- 开发一个高通量,非接触框架来描述微尺度机械超材料的动态特性.
- 为了使线性弹性特性,缩特性和缺陷量化的非破坏性提取.
- 促进动态应用的新材料和微设备的数据驱动发现.
主要方法:
- 用于分析元材料中的MHz波传播特征.
- 使用微型元材料的棒状模块进行测试.
- 开发了一个非接触式的高通量表征框架.
主要成果:
- 在接近10^2s^1的拉伸速度下,达到高达94%的方向依赖和速率依赖的动态硬化.
- 观察到的阻尼性能是构成材料的三倍.
- 通过振动响应的频率变化和实验弹性表面的构造来证明缺陷的量化.
结论:
- 开发的框架使得微尺度机械元材料的动态特性能够进行非破坏性,高通量的表征.
- 这些发现揭示了这些工程材料的显著动态硬化和增强的阻尼.
- 这种方法加速了用于保护结构,医疗超声波和振动隔离的材料的发现.
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