CAREER: Fundamental Problems in Dynamic Fracture Mechanics

所提出的研究的目的是在高剪切载荷下的均匀和双材料系统的动态断裂的基本现象的透彻理解。最近的实验证据表明，在剪切主导裂纹沿沿着界面扩展的过程中，超音速裂纹速度和裂纹面接触的发展。此外，理论证据预测超音速，即使在均匀的材料，在高剪切载荷下，如果均匀的材料表现出内聚型故障响应。在这里，将进行实验和数值分析，以仔细检查接触区的物理细节以及双材料界面和均质材料系统中限制裂纹速度的物理细节。特别强调的是裂纹面摩擦和随后的加热接触过程中的问题。该提案的教育部分描述了一个计划，以改善当前课程的教学实践和增强本科实验室，包括动画课堂演示以及反直觉动力系统的物理演示。

The objective of the proposed research is the thorough understanding of fundamental phenomena in dynamic fracture of homogeneous and bimaterial systems subjected to high shearing loads. Recent experimental evidence during shear dominated crack propagation along interfaces, has shown the development of supersonic crack speeds and crack face contact. In addition, theoretical evidence predicts supersonic speeds even in homogeneous materials, under high shear loading, if the homogeneous material exhibits a cohesive type failure response. Here, experimental and numerical analysis will be conducted to scrutinize the physical details of the contact zone and of limiting crack speedsin bimaterial interface and homogeneous material systems. Special emphasis will be placed on the issue of crack face friction and subsequent heating during contact. The educational part of this proposal describes a plan for improvement of teaching practices in current courses and enhanced undergraduate laboratories, including animated classroom presentations as well as physical demonstrations of counter-intuitive dynamical systems.