CE 5310 Lecture Notes - Lecture 8: Applied Mechanics, Calaveras Fault, Isotropy
Document Summary
Mechanical and chemical effects all impose some types of micro damage to concrete. Detecting distributed microcracking prior to the extended large crack is important to monitoring concrete structures. This signal attenuation can be used to monitor cracks and other damage in concrete as observed in a testing when the ultrasonic transducers are acoustically well coupled to the specimen (suaris & fernando 1987). 1. scattering from the microstructure; generally the scattering process is energy conserving the scattered energy is not lost, but is no longer in phase with the excited wave. Scattering is a complex process dependent upon particle diameter in relation to wavelength, the number of particles per unit volume and the acoustic properties of the particles (gaydeck, et al 1992). When the wavelength is much smaller than the particle size a, diffusion scattering that describes in inhomogeneous section occurs with its magnitude inversely proportional to the mean particle diameter.
