• [2012-10-30]

  Date posted: August 22 , 2012 Probabilistic Aspects of Diagnostics and Prognostics of Metal and Composite Structures Under Repeated Loading

 Title: Probabilistic Aspects of Diagnostics and Prognostics of Metal and Composite Structures Under Repeated Loading   Speaker：Prof. Jan D. Achenbach   Host：Daining Fang   Time：14:00 pm

Date：August 27, 2012

Venue：Yingjie Exchange Center of Peking University    Abstract: The 23rd International Congress on Theoretical and Applied Mechanics held in Beijing will be finished by the time of this lecture. It will be of interest to briefly take stock of the progress that has been achieved over the last 50 years, and to comment on the future of the field. It is evident that the emphasis of research in T&AM is currently directed towards problems of interdisciplinary interest. One such area is quantitative non-destructive evaluation (QNDE) and the related field of structural health monitoring (SHM).     I will discuss the use of waves of ultrasound that can enter opaque materials and “see” defects. These ultrasonic techniques, as well as other methods, are the basis for diagnostic methods in QNDE and SHM. In this presentation I will devote particular attention to probabilistic aspects of diagnostics and prognostics. An example is given for detection and growth of fatigue cracks emanating from rivet holes in a lap joint. An analogous probabilistic approach will be presented for the formation of delaminations in laminated fiber-epoxy composites under repeated impact loading.<span times="" new="" roman'"="">    About the Speaker： Jan D. Achenbach is known for his work on the propagation of waves in solids, with present emphasis on the theory and applications of ultrasonic methods for quantitative nondestructive evaluation, particularly the measurement of elastic properties of thin films by acoustic microscopy as well as laser-based ultrasonics, and the detection of cracks and corrosion in safety-critical structures. In recent years he has worked on the development of probabilistic methods in structural health monitoring for diagnostics and prognostics of damage under repeated loading in structural components. He is the author of a well-known book titled Wave Propagation in Elastic Solids (North Holland, 1973) and a more recent book titled Reciprocity in Elastodynamics (Cambridge University Press, 2003), as well as two other books and numerous papers in technical journals.        Dr. Achenbach is a member of the U.S. National Academy of Sciences and the U.S. National Academy of Engineering. In 2003 he was awarded the U.S. National Medal of Technology for engineering research and education in the use of ultrasonic methods, and in 2005 he received the U.S. National Medal of Science for pioneering the field of quantitative nondestructive evaluation. He has received several other Medals and Awards.        Achenbach studied aeronautical engineering at the Delft University of Technology, Netherlands. He earned his Ph.D. in aeronautics and astronautics, with a minor in mathematics, from Stanford University, California, in 1962. He received an honorary doctorate from Zhejiang University, China, in 2011. He has been a member of the faculty at Northwestern University (Evanston, Ill.) since 1963, and is currently distinguished McCormick School Professor Emeritus in Service.