CAREER: Modeling and Characterization of Microstructure-Induced Toughening in Ceramic Composites with Multiple Micro and Nano Size Scales

9984298本研究涉及先进陶瓷微结构增韧效应的计算和实验表征。重点研究一种性能非常有前途的新型TiB2/Al2O3陶瓷复合材料体系，它将(1)为多种尺寸尺度的显式断裂建模提供一种新的微观力学方法，(2)表征微观结构形态、相长度尺度、成分性质和相间键合对断裂抗力的影响，(3)阐明具有多种尺寸尺度的微观结构的陶瓷复合材料的破坏模式并建立破坏模型。(4)通过微观结构修正确定性能增强机制。结合建模和实验将集中在完整的，时间依赖的过程损伤开始，损伤进展和失效使用时间解决诊断。实验将用于允许应用载荷，时间分辨响应和微观损伤的直接关联。该计划的教育部分包括佐治亚理工学院的本科课程开发，向当地高中学生和教师宣传招聘和工程意识，向少数民族学生宣传招聘，以及向当地少数民族机构宣传。课程改革认识到工程力学教育中缺乏实践实验的课堂教学弊端。这项工作的重点是通过课堂学习与实验室实验的适当结合，加强佐治亚理工学院机械工程本科课程。这项工作的一个新特点是使用了在提议的研究中开发的实验技术，以促进综合工程分析能力的发展。课程创新和推广将使用同样用于研究的设施，提供研究生研究、本科生参与、课程开发和推广的自然协同作用。

9984298This research concerns on the computational and experimental characterization of microstructural toughening effects in advanced ceramics. Focusing on a new TiB2/Al2O3 ceramic composite system with very promising properties, it will (1) yield a novel micromechanical approach for explicit fracture modeling over multiple size scales, (2) characterize the effects of microstructural morphologies, phase length scales, constituent properties, and interphase bonding on fracture resistance, (3) elucidate the failure modes and develop failure models for ceramic composites with microstructures of multiple size scales, and (4) identify mechanisms for property enhancement through microstructural revisions.Combined modeling and experiments will focus on the full, time-dependent process of damage initiation, damage progression and failure using time-resolved diagnostics. Experiments will be used to allow direct correlation of applied loading, time-resolved response, and microscopic damage. The education component of this program consists of undergraduate curriculum development at Georgia Tech, outreach to local high school students and teachers for recruitment and engineering awareness, outreach to minority students for recruitment, and outreach to a local minority institution. The curriculum innovation recognizes the drawback of classroom instruction without hands-on experimentation in engineering mechanics education. This effort focuses on strengthening Georgia Tech's undergraduate curriculum in mechanical engineering through proper integration of classroom learning with laboratory experimentation. A novel feature of this effort is the use of an experimental technique developed in the proposed research to facilitate the development of an aptitude for comprehensive engineering analysis. The curriculum innovation and outreach will use the facilities also used for research, offering a natural synergy of graduate research, undergraduate participation, curriculum development, and outreach.