On Ultrasonic Techniques of Fiber Orientation in CFRP Composite Laminates Using Shear Wave Based on Ultrasonic Polarization

It is very important to detect fiber orientation error in composite laminates because the layup of a CFRP composite laminates affects the properties of the laminate, including stiffness, strength and thermal behavior. An NDE technique for stacking orientation determination would be very beneficial because of layup orientation influence to the laminate stiffness. Usually, it is found that ultrasonic shear wave is pretty sensitive to fiber direction of CFRP composite laminates. An investigation of shear wave ultrasonic technique was carried out in order to detect stacking orientation error for quasi-isotropy composite laminates. Also, a jig is developed for generating a shear wave. A pyramid with an isosceles triangle with two 45° was made of aluminum to generate shear waves using two longitudinal transducers based on ultrasonic-polarized mechanism. Also, the signal splitter was connected to the pulser jack on the pulser/receiver and to the longitudinal transducers. An investigation of shear wave ultrasonic technique was carried out in order to generating shear wave.