Data Reduction Techniques For Analysis Of Wave Propagation In Dissipative Materials

This report discusses two analytical approaches to be used in future studies of stress-wave propagation in rock. The first of the discussions is the development of a method of Fourier analysis of waveforms, the Impulse Train technique. This technique makes use of a discontinuous derivative and the properties of the Dirac delta function for the numerical evaluation of the Fourier transform of a measured time history. The second describes a method whereby a possible stress-strain curve can be deduced from particle velocity histories. Incremental steps in stress are assumed to travel at a velocity determined by the slope of the material stress-strain curve at the stress level of the increment. Equations are derived for the relation of particle velocity to strain and stress. Fortran computer programs for each of the analytical discussions are included as appendixes. (Author).