Low frequency acoustic transducer for a probe for non-destructive testing

A method of generating an acoustic wave for non-destructive testing of a test structure, the method comprising:

• applying an ac electrical signal to a bending actuator for generating a vibration, the bending actuator being rigidly attached to a coupling pin, the vibration generating an acoustic wave for propagation through a portion of the test structure, the bending actuator having a vibration surface and a contact area surrounded by a portion of the vibration surface, and
• contacting the bending actuator by a rigid portion of a mode setting member at the contact area such that, at the contact area, an amplitude of the vibration is substantially suppressed.

A method of receiving an acoustic wave for non-destructive testing of a test structure, the method comprising:

• exposing a bending actuator to the acoustic wave received from the test structure whereby a vibration and an associated ac voltage is generated, the bending actuator having a vibration surface and a contact area surrounded by a portion of the vibration surface, and
• contacting the bending actuator by a rigid portion of a mode setting member at the contact area such that, at the contact area, an amplitude of the vibration is substantially suppressed, the bending actuator being rigidly attached to a coupling pin.