Conventional ultrasonic methods based on ultrasonic characteristics in
the linear elastic region are mainly sensitive to mature defects but are
much less responsive to micro-damage or incipient material degradation.
Recently, nonlinear ultrasonic characteristics beyond the linear
ultrasonic amplitude range have been studied as a method for overcoming
this limitation, and hence, many researchers are engaged in theoretical,
experimental, and various application studies. However, the nonlinear
ultrasonic characteristics are quite exacting compared to the linear
phenomena so that they require vast experience and high proficiency in
order to obtain proper experimental data. Actually, many researchers,
especially beginners including graduate students, have difficulty in
reliably measuring nonlinear ultrasonic characteristics. This book
provides key technological know-how from experts with years of
experience in this field, which will help researchers and engineers to
obtain a clear understanding and high quality data in the nonlinear
ultrasonic experiments and applications.