On October 28, 2022 Bibo Zhong will present his research on Measuring Acoustic Nonlinearity of Elastic Materials Using Modulation of Ultrasonic Waves from 10:00 AM to 12:00 PM in PKI 207 and over ZOOM (https://unl.zoom.us/j/865119035).
Nonlinear parameters play an important role in nonlinear
material characterization, but measurements of absolute
nonlinear parameters are laborious with large error margins.
This presentation presents the equations of wave velocity
changes caused by homogeneous temperature variation and
uniaxial stress in isotropic media and the expression of
nonlinear parameters in terms of thermally induced velocity
change and thermal strain. Nonlinear parameters of an
aluminum sample were experimentally determined by
measuring ultrasonic wave velocity changes in the uniaxial
loading test and the thermal modulation test. Experimental
results showed good agreement between the two test methods.
The nonlinear parameters are also applied to measure the
stress change in a full-scale concrete bridge girder.
More details at: https://unl.zoom.us/j/865119035