应航天航空学院、国际应用力学中心的邀请，美国工程院院士、Int. J. of Solids and Structures主编、 德克萨斯大学奥斯汀分校Stelios Kyriakides教授将来我校进行学术交流。
时间：2016年6月15日下午3：30
地点：教一楼南第二会议室
报告题目：Propagating Instabilities in Materials
Biography:
Prof. Stelios Kyriakides
Professor, Director of Center for Research in Mechanics of Solids, Structures and Materials , John Webb Jennings Chair in Engineering
Dr. Kyriakides' research focuses on instabilities which limit the extent to which solids, structures and materials can be loaded or deformed. He has served on the Cockrell School of Engineering faculty since 1980. He received the National Science Foundation Presidential Young Investigator Award in 1984 and has published more than 200 technical articles and reports. He was a 1997 ASME Fellow and in 2007 he was elected into the National Academy of Engineering.
Propagating Instabilities in Materials
Abstract:
The onset of instability is one of the factors that limit the extent to which materials can be loaded or deformed. In some material systems, instability leads to localization of deformation, which after some growth, is locally arrested. However, under prevailing conditions, the local deformation can propagate or spread to the rest of the material domain. During the propagation of the instability, highly deformed and relatively undeformed “phases” co-exist, while the effort required is often substantially lower than that needed to initiate the instability in the intact material. This presentation encompasses a number of material systems that exhibit propagating instabilities including: shape memory alloys, Lüders banding in mild steels, neck propagation in polymers, propagation of crushing in honeycombs and foams, and kink band broadening in aligned fiber composites and balsa wood. In some of these systems the propagation is exploitable and in others it is catastrophic. The lecture will use results from experiments and modeling to illustrate that, although the physical micromechanical reasons that cause this behavior are different in each material, they share an underlying up-down-up local response.
