Vibration testing based on impulse response excited by laser ablation
Vibration testing based on impulse response excited by laser ablation
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DOI：
10.1016/j.jsv.2010.09.036
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发表时间：
2011-10-10
影响因子：
4.7
通讯作者：
Hosoya, Naoki
中科院分区：
文献类型：
--
作者：
Kajiwara, Itsuro;Hosoya, Naoki
提出了一种基于激光烧蚀激励脉冲响应的振动测试方法。在使用脉冲锤的传统振动测试中，激振力中几乎不存在超过几十千赫的高频元素。本研究采用高功率YAG脉冲激光器在结构表面产生理想的冲击力。用聚焦良好的YAG激光照射金属上的一个点，激光烧蚀是通过在金属上产生等离子体而引起的。结果，由激光烧蚀产生的理想的脉冲激振力被施加到结构上的点。因此，可以测量由于激光激发引起的高频FRF。水滴覆盖在金属上用于调节激光激发的力的大小。采用具有低于40 kHz的九个固有频率的铝块作为测试件。通过比较激光激励、冲击锤和有限元分析得到的试块的频响函数，验证了该方法的有效性。此外，频响函数的测量精度和传感器的灵敏度之间的关系进行了研究。(C)2011爱思唯尔有限公司保留所有权利。
This paper proposes an innovative vibration testing method based on impulse response excited by laser ablation. In conventional vibration testing using an impulse hammer, high-frequency elements of over tens of kilohertz are barely present in the excitation force. A pulsed high-power YAG laser is used in this study for producing an ideal impulse force on a structural surface. Illuminating a point on a metal with the well-focused YAG laser, laser ablation is caused by generation of plasma on the metal. As a result, an ideal impulse excitation force generated by laser ablation is applied to the point on the structure. Therefore, it is possible to measure high-frequency FRFs due to the laser excitation. A water droplet overlay on the metal is used to adjust the force magnitude of laser excitation. An aluminum block that has nine natural frequencies below 40 kHz is employed as a test piece. The validity of the proposed method is verified by comparing the FRFs of the block obtained by the laser excitation, impulse hammer, and finite element analysis. Furthermore, the relationship between accuracy of FRF measurements and sensitivity of sensors is investigated. (C) 2011 Elsevier Ltd. All rights reserved.