Diffuse Fields in Structural Acoustics and Ultrasonics

将开展一个项目来加深我们对线性随机波场的理解，线性随机波场是指遭受了足够的随机散射或反射而失去最大相干性的波。这些场存在于超声波在许多现代材料中的应用，以及在大多数有限弹性体中的足够长的时间尺度上，在其应用是常规声学的混响室中，以及在长期以来一直寻求准确的声学和振动描述的复杂的不规则结构中。拟议的项目包括两个主要推动力。实验室和分析工作将对强非均匀但统计均匀的介质中的超声场进行，特别强调在超声无损评估中的应用，并通过演示人们长期寻求的经典波Anderson局部化现象来寻找这种场中的残余相干效应。第二项工作包括对模型混响室的响应进行大规模计算工作，以期更好地了解本征模式统计，从而对改进的复杂系统结构声学统计模型产生潜在影响。

A project is to be undertaken to further our understanding of linear stochastic wave fields, waves which have suffered sufficient randomizing scatterings or reflections as to lose most coherence. Such fields are present in applications of ultrasonics in many modern materials, and on sufficiently long time scales in most finite elastic bodies, in reverberation rooms for which the application is conventional acoustics, and in complex irregular structures for which accurate acoustics and vibrational descriptions have long been sought. The proposed project consists of two main thrusts. Laboratory and analytic work will be conducted on ultrasonic fields in strongly heterogeneous but statistically homogeneous media, which special emphasis on applications in ultrasonic nondestructive evaluation and on seeking the effects of residual coherence in such fields by demonstration the long-sought phenomenon of classical wave Anderson Localization. A second thrust consisting of large scale computational work on the responses of model reverberation rooms will also be conducted, with a view towards better understanding of eigenmode statistics with consequent potential impact on improved statistical models of the structural acoustics of complex systems.