Keynote Speaker

Abstract: Split Hopkinson bar (SHB) has been widely used for testing the dynamic mechanical behavior of materials. However, it is hard to involve complex stress conditions in traditional SHB due to its intrinsic characteristics. Electromagnetic Hopkinson bar (E-Hopkinson bar) has been recently proposed as a solution. Different from traditional SHB, the stress pulse of E-Hopkinson bar is generated directly by electromagnetic force. Therefore, the stress pulse that loads the specimen can be accurately controlled. With this advantage, some experiments that cannot be done with traditional SHB can be conducted by E-Hopkinson bar technique. In this case, we introduced briefly the basic principles of E-Hopkinson bar. Some lasted tests, such as symmetrically dynamic compression/tension of materials, testing technique for brittle materials, dynamic Bauschinger effect of metals, intermediate strain rate tests, trapezoidal stress pulse generation and dynamic multi-axial tests were also introduced. This new technique will be helpful for those researchers in the field of solid mechanics, especially when strain rate and complex stress condition are involved.

Biography: Dr. Yulong Li is the Dean of Civil Aviation School and a Chair Professor in Department of Aeronautical Structure Engineering in Northwestern Polytechnical University (NPU). He received his Ph.D. degree in Solid Mechanics from NPU in 1992 and became a Professor in 1995. From 1996 to 2000 he worked as a post-doctor and subsequently a senior research scientist in University of California San Diego (UCSD) and Johns Hopkins University (JHU). He was a visiting professor of Tokyo University of Science in Japan, a visiting professor of Université Pierre et Marie Curie of France and a visiting professor of JHU. His research interests include dynamic response and failure of structures under impact loading, constitutive relationship for materials, experimental techniques in impact dynamics, as well as, numerical simulation of materials and structures under impact. He has authored more than 400 papers, as well as over 50 patents and 4 book chapters.