RIA: Experimental Simulation of Crack Initiation at Bimaterial Interfaces due to Mechanical and Thermal Loads

准静态和动态裂纹的实验研究 在材料界面处的引发和生长， 机械和热负荷，将进行。 研究 将有助于更好地理解界面失效 主要控制断裂行为的机制 多相材料如聚合物和金属基复合材料， 金属填充的复合材料，以及粘合剂粘合和薄膜 印刷受体. 建议的工作是有关裂纹萌生 在受控加载条件下的生长模拟， 双材料标本 界面裂纹尖端变形将是 在断裂开始之前和断裂开始时进行光学测量。 一个新 开发的，真实的时间，全场光学技术，“相干 梯度传感”（CGS）将用作实验工具 用于测量界面裂纹附近的变形。 从这些 高分辨率光学测量，局部裂纹尖端参数，裂纹尖端应力分布 如复应力强度因子和裂纹尖端模态混合度 将被推断。 光学测量将使我们能够寻找 局部裂尖参数与 外部/材料参数，如远程加载和材料 属性不匹配。 这将为识别 显著影响裂纹萌生的参数， 界面和建立界面失效标准。

Experimental research, dealing with quasi-static and dynamic crack initiation and growth at material interfaces subjected to mechanical and thermal loading, will be carried out. The research will contribute to a better understanding of interfacial failure mechanisms which predominantly control the fracture behavior of multi-phase materials such as polymer and metal matrix composites, metal filled composites, and of adhesive bonds and thin films on substrates. The proposed work is concerned with crack initiation and growth simulations under controlled loading conditions in bimaterial specimens. Interfacial crack tip deformations will be optically measured prior to and at fracture initiation. A newly developed, real time, full field optical technique, 'Coherent Gradient Sensing' (CGS), will be utilized as an experimental tool for measuring deformations near interfacial cracks. From these high resolution optical measurements, local crack tip parameters such as complex stress intensity factor and crack tip mode mixity will be inferred. The optical measurements will allow us to seek relationships between the local crack tip parameters and external/material parameters such as remote loading and material property mismatch. This will provide valuable data for identifying parameters which significantly influence crack initiation at interfaces and for establishing interfacial failure criteria.