Nonlinear Ultrasonic Nondestructive Evaluation of Isotropic and Composite Plates: Theory and Experiment

这个项目是研究金属（MMC）和陶瓷（CMC）基复合材料结构中接头的基本方面。研究理念强调对潜在力学的理解及其与微观结构和加工的关系。研究方法基于相对简单的接头几何形状的设计、制造、表征和分析，从而可以研究物理问题的单个特征及其潜在机制，例如由纤维端定义的界面强度和相关的脱粘过程。多晶氧化铝纤维增强铝合金的MMC研究将集中在多晶氧化铝纤维增强铝合金上，而CMC接头将通过将多晶氧化铝浆料真空渗透到按规定不连续层排列的多晶氧化铝纤维布中来制备。通过适当控制烧结温度和其他制造参数，可以改变接头的显微组织和抗分层性能。重点将是确定相关机制及其与加工的关系，通过微观结构和缺陷。＊＊＊

9634927 Leckie This project is to study the fundamental aspects of joints in metal (MMC) and ceramic (CMC) matrix composite structures. The research philosophy emphasizes the understanding of the underlying mechanics and its relationship to microstructure and processing. The research approach is based on the design, manufacturing, characterization and analysis of relatively simple joint geometries which allow the study of individual features of the physical problem and its underlying mechanisms, e.g. the strength of the interfaces defined by the fiber ends and the associated debond process. The MMC research will focus on aluminum alloys reinforced with polycrystalline alumina fibers while the CMC joints will be fabricated by vacuum infiltration of multi-alumina slurries into polycrystalline alumina fiber cloth arranged in layers with prescribed discontinuities. The microstructure and delamination resistance of these joints can be modified by suitable control of the sintering temperature and other manufacturing parameters. The emphasis will be identifying the relevant mechanisms and their relationship to processing via microstructure and defects. ***