Improved FE simulation of ultrasound in plastics

Some UK and US nuclear power stations have begun introducing high-density polyethylene (HDPE) pipes to certain cooling water circuits. HDPE offers improved performance over existing pipe materials, such as cast iron, by not corroding in-ternally or externally, yet occasional defects form in HDPE pipe fusion joints at the production stage. This necessitates suitable volumetric NDE to safely and reliably assess joint integrity. Ultrasonic NDE is the most viable current technique, but improved inspection capability is needed, given that the challenges of NDE of plastics differ significantly from those of metals. This also necessitates an accurate and reliable wave propagation simulation technique, such as finite-element (FE) modelling. Accurate FE modelling of ultrasound in high-density polyethylene (HDPE) must account for frequency-dependent behaviour but, the most ap-parent way to do so – frequency domain FE modelling – is prohibitively computationally expensive and potentially impossible to solve for all ...