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報告題目：In Situ Dynamic Damage Visualization and X-ray Diffraction in Materials under Impact Loading
報告人：陳為農（Wayne Chen） 教授
時間：10月8日下午14：30－16：30
地點：11#1020
主辦單位：科學技術研究院、“2011計劃”辦公室、國際交流與⏭➰處
承辦單位：304am永利集团
報告人簡介：Professor Wayne Chen received his Ph.D. in Aeronautics at California Institute of Technology in 1995. He is currently a Professor of Aeronautics, Astronautics and Materials Engineering at Purdue University in West Lafayette, Indiana. His research interests are in dynamic experimental technique development and dynamic material characterization. The research results from his group have been published in a book and over 140 journal articles. He is a University Faculty Scholar at Purdue, a Fellow of American Society of Mechanical Engineers, a Fellow of Society for Experimental Mechanics, and an Associate Fellow of American Institute of Aeronautics and Astronautics. He serves as an Associate Editor of the Journal of Applied Mechanics, as a member of the Editorial Advisory Board of the International Journal of Impact Engineering, and as a member of the United States National Committee on Theoretical and Applied Mechanics.
報告内容簡介：Kolsky bars (SHPBs) are common high-rate characterization tools for dynamic mechanical response of materials. For materials under impact loading, the failure processes is a critical aspect in their mechanical response. Thus, it is desired to track the damage evolution in real time during the dynamic deformation of the specimens at multi-scales, which has not been possible except for a few transparent materials under high-speed imaging. In this presentation, the successful process of amalgamating both the high-speed X-ray imaging and X-ray diffraction capabilities present at the Advanced Photon Source beamline 32ID-B (Argonne National Laboratory) and the proficiency of high-rate loading offered by the Kolsky compression/tension bar apparatus will be discussed. The verification of system effectiveness is expressed via impact on various material systems. Analysis of the material systems being loaded with the Kolsky bar apparatus while visually tracking deformation and damage history via Phase Contrast Imaging and local deformation/phase transformation via high-speed X-ray diffraction demonstratively depicts the effectiveness of the novel union among these powerful techniques, thereby allowing for in-situ image and microstructure analysis inside of the material system at high loading rates.