Air-coupled ultrasonic (ACU) is a contactless ultrasonic measurement method which has
become increasingly popular for material characterization. This is due to a growing number …

In this paper analyses of non-contact elastic wave generation based on an air-coupled
transducer (ACT) are presented. Authors compared contact piezoelectric based (PZT) wave …

This study investigates the application of air-coupled ultrasonics for nondestructive, non-
contact characterization of polymer and polymer-matrix composite samples. A lot of progress …

An air-coupled ultrasonic method, focusing on the problem that weak bonding interface is
difficult to accurately measure using conventional nondestructive testing technique, is …

Air-coupled ultrasound was used for assessing natural defects in wood boards by through-
transmission scanning measurements. Gas matrix piezoelectric (GMP) and ferroelectret (FE) …

In this work, we model ACU transmission in delaminations, with focus in the interference
effects resulting from multiple ultrasonic reflections within the delamination layers and the …

This project evaluated a low‐cost sponge phantom setup for its capability to teach and study
A‐and B‐line reverberation artifacts known from lung ultrasound and to numerically simulate …

Flexural ultrasonic transducers are principally used as proximity sensors and for industrial
metrology. Their operation relies on a piezoelectric ceramic to generate a flexing of a …

A prestressed bolt connection is one of the crucial connection types in timber structures. The
daily checking and maintenance of bolt connections have to be carried out in order to avoid …

Air-coupled ultrasound (ACU) is used in through transmission to detect delamination, rot,
and cracks in wood without altering the structure permanently. Novel ferroelectret …