Physical Mechanisms Governing the Intersonic and Supersonic Decohesion of Bimaterials: Effects of Interfacial Strength, Loading Rate and Confining Pressure

控制双材料间声速和超声速消聚的物理机制：界面强度、加载速率和围压的影响

• 批准号: 9813100
• 负责人: Ares Rosakis
• 金额: $ 24.38万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-02-01 至 2002-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9813100&HistoricalAwards=false
• 关键词: Physical; Mechanisms; Governing; Intersonic; Supersonic

An analytical study will be conducted of the physical phenomena associated with highly dynamic decohesion of bimaterial interfaces and simple unidirectional composites. Specific goals of the project are to establish the necessary conditions for dynamic bimaterial decohension in various regimes (subsonic, intersonic, and supersonic) and to characterize the associated physical phenomena. To accomplish these goals, material combinations and processing techniques will be chosen that allow for the variation of interfacial strength, confining pressure and mismatch of mechanical properties (most importantly wave speeds) across the interface. In addition, loading configurations will be selected that can provide a range of impact velocities. Analytical studies will be undertaken to develop a theoretical framework by which the experimentally observed transient intersonic and supersonic shear dominated mechanical fields can be qualified in terms of appropriate fracture parameters. Thermal fields resulting from the observed large scale frictional contact and the associated energy dissipation will also be investigated. Experimental measurements of the deformation fields and thermal fields in the vicinity of a dynamically loaded or propagating interfacial crack will be performed in real time using ultra-high speed optical and thermographic diagnostic techniques. The deformation fields will be characterized using high speed photography in conjunction with two optical techniques: Coherent Gradient Sensing (CGS) and dynamic photoelasticity. Temperature fields near shear dominated intersonic and supersonic intrfacial cracks willb measured using a recently developed high speed infrared camera in order to study local mechanisms of energy dissipation.

一项分析研究将对与双层界面和简单的单向复合材料的高度动态脱粘相关的物理现象进行。 该项目的具体目标是在各种方案（亚音速，间值和超音速）中建立动态双层断裂的必要条件，并表征相关的物理现象。为了实现这些目标，将选择材料组合和加工技术，以允许界面强度，机械性能（最重要的是波速）的界面强度变化。 此外，将选择可以提供一系列冲击速度的加载配置。 将进行分析研究以开发一个理论框架，通过该框架，可以通过适当的裂缝参数来实验观察到的瞬态间隔和超音速剪切主导的机械场。 还将研究由观察到的大规模摩擦接触和相关能量耗散产生的热场。 将使用超高速度光学和热学诊断技术实时进行变形场和热场的变形场和热场的实验测量。 变形场将使用高速摄影与两种光学技术结合进行表征：相干梯度感应（CGS）和动态光弹。 剪切附近的温度场占主导地位的间隔和超音速室内裂纹将使用最近开发的高速红外摄像头测量，以研究局部能量耗散机制。