An Advanced Nonlinear Signal Analysis Method For Damage Detection in Geomaterials

An algorithm is described which enables us to evaluate the Volterra kernels and the corresponding transfer functions. This method is then used to detect the cracking threshold of the geomaterials under loading. The responses of a sample of sandstone under axial leading and subjected to ultrasonic excitation are analyzed. The occurrence of microcracking is characterized by the changes in the linear and nonlinear parts of the measured signal energy.