Md. Tawhidul Islam Khan, Ph.D.

Keynote Lecture 7: Title: Acoustic Emission Technique, A Nondestructive Monitoring Tool for Damage Detection and Evaluation
	Md. Tawhidul Islam Khan, Ph.D. Associate Professor Dept of Mechanical Engineering Graduate School of Science and Engineering Saga University, Saga, Japan
Abstract : Acoustic emission (AE) signals that are generated due to the sudden rearrangements of stresses inside a material as elastic waves, are widely used in non-destructive testing (NDT) of material cracking especially in health monitoring of structures for damage detection as well as in plant maintenance etc. When a body is subjected to an external stimulus (in the form of changing pressure, load, or temperature), any micro fracture inside the body releases energy in the form of AE wave which is received by AE sensor, later on, is converted to electrical signals termed as AE signals for internal inspection. This evaluation technique is termed as acoustic emission technique. In early stage, major importance was given on studying the AE characteristics during the deformation and fracture on various materials (by J. Kaiser in Germany in 1950, by B. H. Schofield in the U. S. in 1954). However, as the time passed, lots of researches have been conducted in different fields about behavioral formulation, theoretical explanation as well as experimental validation of this technique in AE signal generation, propagation and inspection with various kinds of deformations as an important health monitoring tool for NDT. In the present topic, features outlook of AE based nondestructive monitoring technique perspective to the damage detection and evaluation are planned to be elaborated. Basic theories, experiments related to the material cracking behavior are included to the presentation. Source localization of internal damage that has become an important characteristic feature in AE technique based NDT is also planned to be elaborated to this presentation. Furthermore, AE technique perspective to the advanced applications are also summarized in the present topic. Several practical research results are planned to discuss in the proposed presentation as well. Biography : Dr. T. I. Khan graduated from the Department of Mechanical Engineering, Khulna University of Engineering and Technology (KUET), Bangladesh in 1991. He completed his masters and doctorate degrees from Saga University, Japan in 1997 and 2003 respectively. After his PhD, he awarded the JSPS postdoctoral fellowship and continued his research at Saga University until September, 2007. Since October 2007 till to date he has been working as an Associate Professor in Graduate School of Science and Engineering, Saga University, Japan. His current research interests are acoustic emission (AE), bio-medical imaging, NDT,　diagnostics, machine learning, moiré topography, noise reduction and so on. He is the author of more than 90 technical papers. He is actively holding the membership of SICE, ASJ, JSME, JSNDI, IIAV and IEB.