Elastic Wave Scattering by Surface-Breaking Cracks and Cavities

表面破裂裂纹和空腔的弹性波散射

• 批准号: 0098418
• 负责人: David Bogy
• 金额: $ 22.63万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0098418&HistoricalAwards=false
• 关键词: Elastic; Wave; Scattering; Surface; Breaking

Abstract: The project is intended to develop practically efficient and theoretically rigorous solutions to a broad class of problems in technology with specific applications to problems in non-destructive evaluation by elastic wave scattering from surface breaking cracks and cavities in structures. In the method, wave fields are represented through auxiliary phase and amplitude functions. The phase function, known also as the "eikonal", is determined by the classical Hamilton-Jacobi method in dynamics. The amplitude function is determined by the random walk method whose systematic use is the core innovation of the project. This method provides the description of the wave fields by extremely simple and explicit probabilistic formulas. The proposed work is expected to significantly affect most areas dealing with the modeling of complicated phenomena in continua. Such areas as non-destructive evaluation, geophysics, acoustics, radar, telecommunication technologies, and other areas dealing with wave propagation are expected to especially benefit from the project. Such considerable impact is provided by the use of a novel approach that combines the simplicity of asymptotic methods with the versatility of direct numerical methods. The method to be utilized is compatible with conventional methods, and it employs scalable algorithms with low memory requirements and with unlimited capability for parallel processing. It is an approach that is ideal for the present state of development of computational facilities, relying on theoretical developments in statistics that have occurred since the 1920's.

摘要：该项目旨在开发实用有效且理论上严格的解决方案，解决广泛的技术问题，并具体应用于通过结构中表面破裂裂缝和空腔的弹性波散射进行无损评估的问题。该方法中，波场通过辅助相位和幅度函数来表示。相函数，也称为“eikonal”，由动力学中经典的 Hamilton-Jacobi 方法确定。幅值函数由随机游走法确定，其系统运用是该项目的核心创新点。该方法通过极其简单和明确的概率公式提供了波场的描述。 预计所提出的工作将显着影响大多数处理连续体复杂现象建模的领域。无损评估、地球物理学、声学、雷达、电信技术以及其他涉及波传播的领域预计将特别受益于该项目。 如此巨大的影响是通过使用一种新颖的方法来实现的，该方法将渐近方法的简单性与直接数值方法的多功能性相结合。所使用的方法与传统方法兼容，并且它采用具有低内存需求和无限并行处理能力的可扩展算法。这种方法非常适合目前计算设施的发展状况，依赖于 1920 年代以来统计学理论的发展。