Longitudinal wave attenuation measurements in ductile cast iron

The predominantly scattering-induced attenuation coefficient of a beam of longitudinal plane waves travelling in three different directions through a ductile cast iron specimen is measured as a function of the frequency. The experimental data is obtained by mapping the incident and the transmitted ultrasonic field, and by evaluating the energy loss experienced by each plane wave component of the beam. The high accuracy of this so-called energy method has been previously demonstrated, and its superiority over conventional approaches is shown here once again. The experimentally evaluated attenuation coefficient of high accuracy is an important input parameter for mathematical models, which play an increasingly important role in non-destructive testing by allowing simulations of inspection results without the time and cost of constructing specimens and performing measurements.