裂纹长度对引导波声辐射的导向性影响:对辐射模式的数值研究
1Applied Research Laboratories, The University of Texas at Austin, United States of America.
Ultrasonics
|November 2, 2023
概括
金属板上的裂纹尖端的声学辐射 (AE) 受裂纹大小的影响. 一个新的度量,辐射偏移 (RO),量化了这种效应,可以帮助估计裂长度.
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:
- 声学发射 (AE) 是一种现象,即短暂的弹性波是由应力材料快速释放的能量产生的.
- 了解AE指令对于准确定位和描述损坏源,如裂至关重要.
- 有限裂纹表面可以改变AE波的传播和特征.
研究的目的:
- 为了研究有限裂纹表面大小对裂纹尖端AE导向性的影响.
- 分析AE波在具有不同裂纹长度的薄金属板中产生和传播的情况.
- 引入和评估基于AE的裂长度估计的新型指标.
主要方法:
- 使用3D时间域有限元模型来模拟AE生成.
- 该研究的重点是首次到达的定向效应,通过引导模式分解解释AE.
- 模拟涵盖了0到10个板厚的裂纹长度和一个半无限的裂纹,频率约为0.1-0.4 MHz-mm.
主要成果:
- 在基本对称 (S0) 和剪切水平 (SH0) 引导模式下,观察到裂尖背后的声辐射辐射增加.
- 这种增加在所有模拟的裂长度中都被注意到,包括半无限的情况.
- 引入了一种新的度量,辐射偏移 (RO),以量化这种观察到的行为.
结论:
- 有限裂纹表面显著影响AE导向性,在裂纹尖端后面观察到辐射增加.
- 辐射偏移 (RO) 度量有效地捕捉了裂几何学对AE的影响.
- 开发的RO指标显示了基于AE的金属结构裂纹长度估计的潜力.
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