RIMI: Fast Detection of Flaws and Residual Stresses in Composite Materials by a Real-Time Nondestructive Laser Technique

纤维增强有机基复合材料正被用于 或被提议作为许多生物的主要和次要结构， 军事和商业应用。 缺陷的存在 并且这些复合材料中的残余应力通常是由于 通过制造和/或安装过程。 此外，委员会认为， 这些先进材料的结构特性是已知的 受使用中环境条件的影响 （湿度、温度、压力、冲击等）。 这些 条件诱发残余应力和微裂纹， 复合材料，并且可以不可逆地降解纤维/基质 接口. 这项研究旨在开发和展示 一种新的自动无损检测技术，激光散斑剪切 干涉测量法，能够快速确定剩余的 应力和定位复合材料中的缺陷。 通过允许 基本的实时测量将在现场进行， 可以实现工程模型的开发，从而 将有助于改善复合材料的基础研究 材料在各种操作条件下。 的 技术是可行的，适合在 制造环境或部门/维修设施以及 领域 两名少数民族本科生和一名研究生 工程系学生将协助校长 研究人员在拟议的研究。

Fiber reinforced organic matrix composites are being used or proposed as primary and secondary structures for numerous military and commercial applications. The presence of flaws and residual stresses in these composites are often caused by the fabrication and/or installation process. Moreover, the structural behavior of these advanced materials is known to be affected by in-service environmental conditions (humidity, temperature, pressure, impact, etc.). These conditions induce residual stresses and microcracking in the composite, and can irreversibly degrade the fiber/matrix interface. The proposed research is designed to develop and demonstrate a novel automated NDE technique, laser speckle shearing interferometry, capable of rapidly determining the residual stresses and locating flaws in composites. By allowing fundamental real-time measurements to be made in situ, the development of engineering models can be attained, and thus will contribute to improved basic studies of composite materials under various operational conditions. The technique is viable and suitable for operation in a manufacturing environment or dept/repair facility and in the field. Two minority undergraduate students and one graduate student of engineering will assist the principal investigator in the proposed research.