Sabra Karim G, Srivastava Ankit, Lanza di Scalea Francesco, Bartoli Ivan, Rizzo Piervincenzo, Conti Stephane
School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405, USA.
J Acoust Soc Am. 2008 Jan;123(1):EL8-13. doi: 10.1121/1.2820800.
Recent theoretical and experimental studies in a wide range of applications have demonstrated that Green's functions (impulse responses) can be extracted from cross-correlation of diffuse fields using only passive sensors. This letter demonstrates the passive-only reconstruction of coherent Lamb waves (dc-500 kHz) in an aluminum plate of thickness comparable to aircraft fuselage and wing panels. It is further shown that the passively reconstructed waves are sensitive to the presence of damage in the plate as it would be expected in a typical "active" guided wave test. This proof-of-principle study suggests the potential for a structural health monitoring method for aircraft panels based on passive ultrasound imaging reconstructed from diffuse fields.
近期在广泛应用领域开展的理论与实验研究表明，仅使用无源传感器就可以从扩散场的互相关中提取格林函数（脉冲响应）。本文证明了在厚度与飞机机身和机翼面板相当的铝板中，仅通过无源方式就可以重建相干兰姆波（直流 - 500千赫兹）。进一步表明，被动重建的波对板中损伤的存在很敏感，这正如在典型的“主动”导波测试中所预期的那样。这项原理验证研究表明，基于从扩散场重建的被动超声成像，有可能为飞机面板开发一种结构健康监测方法。
