Optimization and comparison of ultrasonic techniques for NDT control of composite material elements

This work contains an overview of innovative procedures related to the optimization of non-destructive control ultrasonic techniques for defect investigation on composite plates. The inspection procedure improvement allows developing ideal ultrasonic setup and methods, giving the operator appropriate criteria and guidelines in terms of equipment, material and control procedures. Ultrasonic inspections are conducted on different GFRP laminates with artificial defects; tests are improved using special parts designed for probe positioning and contact conditions on inspected components. The data processing of UT procedures allows comparing detection sensitivity of different probe frequencies and plate material behavior. Contact ultrasonic method presents best results for GFRP plates using 1 MHz Olympus A103S probe, detecting small defects with maximum signal amplitudes. Finally, a statistical study is performed for repeatability demonstration of UT inspections. ED 2018 The Authors. Published by Elsevier B.V.