TOKYO-Toshiba Corporation (TOKYO: 6502) has developed a Sliding Sheet-Lattice Matrix (SSLM) for ultrasonic nondestructive testing in infrastructure maintenance and inspections. The developed SSLM does not require the application of a liquid couplant, such as the gel applied to human bodies for ultrasonic examinations during health checkups, and furthermore combines high performance for passing ultrasonic waves (ultrasonic propagation) with smooth device operability.
Nondestructive testing is an inspection evaluating internal defect and its form or size in an object without damaging it, and ultrasound, which is harmless to the human body, is widely used in such inspections. Liquid or gel couplant are often used in ultrasonic inspections, especially when inspecting the human body, because they both provide high levels of ultrasonic propagation and smooth operations. However, in the field of infrastructure maintenance and inspection, liquids can seep into the interior of inspection targets, leading to failure or deterioration of the applied structures or equipment. Minimizing such effects requires additional work, so applications to infrastructure now also uses adhesive sheets of solid couplant, but there is generally a trade-off between ultrasonic propagation and smooth operations, leading to issues such as increased work times.
Toshiba has developed SSLM comprising a proprietary soft sheet and lattice material to realize both ultrasonic wave propagation and smooth operability. The lattice material allows low-friction movement over structure and equipment surfaces when changing inspection positions, and when inspecting, applying a load to press the SSLM against the object that is the target of an inspection allows propagation of ultrasonic waves, giving it rapid response characteristics. Ultrasonic nondestructive testing requires taking measurements from many locations following the surface of the inspected object, and thus use of the developed SSLM should result in significant time reductions compared with the inspection times seen when using conventional adhesive sheets(*1). In addition, compared with conventional ultrasonic nondestructive inspection methods using a liquid couplant, SSLM eliminates the need for masking areas outside of the inspection area before the inspection and removing applied liquid couplant after inspections, thereby contributes to improved efficiency and automation of maintenance and inspections. Furthermore, it enables be applied to objects that were previously difficult to apply, due to the difficulty of removing liquids.
Toshiba will present details of this development at the 43rd Symposium on Ultra Sonic Electronics (USE2022) (*2), which will be held in Kyoto from November 7.