Design of a low profile array transducer in d15 mode for high angled shear wave generation

Shear wave inspection is generated from mode conversion of longitudinal waves, using a selected, angled wedge positioned between the transducer and the test specimen. However, in certain scenarios where access is restricted the combination of the transducer and the wedge can be too cumbersome for in situ deployment. In this work, a low profile, linear ultrasound array transducer is proposed to generate shear waves via direct coupling to the component surface precluding the requirement for a wedge. The array transducer was designed using finite element modelling, and a prototyped array was manufactured with 32 elements and operating frequency at ∼2MHz. Preliminary imaging results has shown the shear wave beam generated can be operated at high angles up to 80°.