MMAE Seminar - Dr. Jan D. Achenbach - A New Use of the Elastodynamic Reciprocity Theorem

Armour College of Engineering's Mechanical, Materials & Aerospace Engineering Department will welcome Dr. Jan D. Achenbach, Walter P. Murphy and Distinguished McCormick School Professor Emeritus of Civil and Environmental Engineering, Engineering Sciences and Applied Mathematics, and Mechanical Engineering at Northwestern University McCormick School of Engineering. Dr. Achenbach will present his lecture A New Use of the Elastodynamic Reciprocity Theorem.

Abstract

For linearly elastic bodies the elastodynamic reciprocity theorem provides an integral relation over the interior of a body V and its boundary S, which involves the displacements, the surface tractions and the body forces of two elastodynamic states, State A and State B. In this talk it is shown that the theorem can be used to solve problems for guided waves, such as surface waves and waves in waveguides, which only requires the general form of the wave motion of State A, whose amplitude is to be determined, and only the general form of State B, which is a virtual wave. Examples to be discussed are the surface wave generated by a concentrated load on a homogeneous half space and a half space with depth-dependent properties, the scattering by a sub-surface crack and the scattering of torsional waves by a circumferential defect, such as corrosion, in a pipe.

Speaker Bio

Jan D. Achenbach is an expert on solid mechanics, with a major emphasis on the theory and applications of ultrasonic methods to quantitative non-destructive evaluation, particularly the measurement of elastic properties of thin films by acoustic microscopy, and the detection of cracks and corrosion in safety-critical structures. In recent years he has contributed to the development of probabilistic methods for structural health monitoring of fatigue damage in structural components for the purposes of Diagnostics and Prognostics. For the last three years he has worked on a comprehensive model for the rate of stress corrosion cracking. He is the author of a well-known book entitled Wave Propagation in Elastic Solids (Elsevier Science, 1973, still available in paperback), and a recent book entitled Reciprocity in Elastodynamics (Cambridge University Press, 2004), as well as numerous papers in technical journals.

Amongst a number of prestigious awards, Dr. Achenbach was named to the National Academy of Engineering in 1982, the National Academy of Sciences in 1992, and elected a Fellow of the American Academy of Arts and Sciences in 1994. He was awarded the 2003 National Medal of Technology, and in 2005 the National Medal of Science.
Earn Engineering Themes Credit in Energy & Security by attending this event.