Ultrasonic non-destructive testing

摘要

An apparatus and method for ultrasonic non-destructive testing provides an elongate strip of ultrasound transmissive material coupled at a proximal end to an object under test. The elongate strip has a transverse cross-section with a width and thickness giving an aspect ratio greater than unity and matched to the ultrasonic transducer such that excitation induces a substantially non-dispersive ultrasonic signal to propagate along the elongate strip to the proximal end and to enter the object under test. These non-dispersive pulses are particularly suited for time-of-flight measurements, thickness measurements, crack measurements and the like. The elongate strip helps to separate the transducer from a potentially hostile environment associated with the object under test. The elongate strip also has a large area of contact with the object under test allowing efficient transmission of energy into the object under test.

主权项

1. Apparatus for ultrasonic non-destructive testing of a solid object, the apparatus comprising:
an elongate strip of ultrasound transmissive material, said elongate strip having a transverse cross-section with a width and a thickness giving an aspect ratio greater than unity, a proximal end and a distal end; an ultrasonic transducer coupled to said elongate strip and matched thereto such that excitation of said ultrasonic transducer induces non-dispersive ultrasonic shear wave signals to propagate in a propagation direction along said elongate strip to said proximal end, said signals being formed of components of different frequencies having wavelengths extending from λshort to λlong and being polarized in a direction perpendicular to said propagation direction; coupling means for coupling said proximal end to a surface of a solid object, wherein said non-dispersive signals are coupled into the solid object; and an ultrasound receiver configured to receive reflected signals from the solid object that are non-dispersive ultrasonic shear wave signals and are polarized in a direction perpendicular to a propagation direction of the reflected signals; wherein said thickness is less than 2.5 λshort and said width is greater than 5 λlong.