Ultrasonic Testing of Glass Fiber-Reinforced Polymer Composites Used in High-Voltage Insulating Components

Abstract

Due to their high strength-to-weight ratio and good dielectric properties fiber-reinforced polymers have gained significant interest in different industrial fields, including the automotive, aerospace, and energy sectors. Despite this attention, the evaluation of the properties of polymer-based composite components, both as part of post-manufacturing control and in-service checks, remains challenging. In this article, ultrasonic testing is investigated as a nondestructive approach for the quality evaluation of high-voltage composite insulators. Classical phase array ultrasonic testing is compared with the total focusing method. The results are validated using computed tomography and a destructive testing approach. It was demonstrated that the proposed ultrasonic testing (UT) technique detected microcracks and small voids in the analyzed samples similar to the reference testing approaches. It was also proved that the water immersion total focusing method can be successfully implemented in a full-scale production process if the scanning and data analysis tasks are properly automated. Since the pilot solution was developed to evaluate objects with relatively simple shapes, further work is needed to cope with more complex geometries.