Devices for maintaining crawler alignment on complex-shaped blades and for enabling the blade crawler to traverse over trailing edge protrusions. Using ball and socket bearings or air pads in place of alignment wheels, the crawler will be able to track along complex-geometry rotor blades, propellers and other airfoils. Using an oversized-diameter roller, a semi-flexible roller, or a dual-roller arrangement, the crawler will be able to traverse over trailing edge protrusions.

Method for ultrasonic characterization of a medium, comprising generating a series of incident ultrasonic waves, generating an experimental reflection matrix R.sub.ui(t) defined between the emission basis (i) as input and a reception basis (u) as output, and determining a focused reflection matrix RFoc(r.sub.in, r.sub.out, δt) of the medium between an input virtual transducer (TV.sub.in) calculated based on a focusing as input to the experimental reflection matrix and an output virtual transducer (TV.sub.out) calculated based on a focusing as output from the experimental reflection matrix, the responses of the output virtual transducer (TV.sub.out) being obtained at a time instant that is shifted by an additional delay δt relative to a time instant of the responses of the input virtual transducer (TV.sub.in).

A system for inspecting flexible pipelines comprises a data analyzer, a data collector and an ultrasonic transducer. Further, the ultrasonic transducer is adapted to propagate shear wave into the annulus of the flexible pipeline. The data collector further comprises a data store and a communicator. Further, the system is capable of differentiating flooding and non-flooding condition of the annulus of the flexible pipeline which is subjected to high pressure. Using the system, an indicator of a flooded or non-flooded condition within the flexible pipeline may be calculated using transmitted and detected reflective waves or the lack of detected reflective waves.

Methods for non-destructive testing of engineering materials. In one aspect, a method can be used to calculate residual longitudinal and annular welding stresses in welded joints and can be used to assess the quality of pipeline welds according to the criterion of the level of residual stresses and to determine the initial parameters for the pipeline strength calculation. In some aspects, the method enables independent calculation of the longitudinal and hoop residual stresses. Thus, the stresses can be calculated in the seam metal of the pipelines welds, where they reach their maximum values. The method can be used to test a pipeline section using an ultrasonic echo method to measure the propagation time for longitudinal waves and transverse waves polarized along and across the pipe axis. The measurement results define the distinguishing features of the stress state of a welded joint for a specific type of pipe by numerical modeling.

A reflection-diffraction-deformation flaw detection method employs a transverse wave oblique probe. When an ultrasonic transverse wave encounters a defect during propagation, a reflected wave, a diffracted wave, and a deformed wave are generated. Through a comprehensive analysis of these waves, the presence or absence of the defect is determined by the reflected wave having reflection characteristics and the diffracted wave having the diffraction characteristics. The shape and size of the defect are determined by the deformed wave having deformation characteristics, namely the deformed surface wave generated at the endpoints of the defect which propagates on the defect surface. Furthermore, by the combination of paths trailed by the deformed surface wave, the deformed transverse wave, and the deformed longitudinal wave that are generated by the defect as well as that trailed by the transmit transverse wave, causes of all those waves in the screen can be revealed.

Methods for processing data acquired using ultrasound elastography, in which shear waves are generated in a subject using continuous vibration of the ultrasound transducer, are described. The described methods can effectively separate shear wave signals from signals corresponding to residual motion artifacts associated with vibration of the ultrasound transducer. The systems and methods described here also provide for real-time visualization of shear waves propagating in the subject.

Methods for measuring mechanical properties of an object or subject under examination with an ultrasound system and using unfocused ultrasound energy are provided. Shear waves that propagate in the object or subject are produced by applying unfocused ultrasound energy to the object or subject, and measurement data is acquired by applying focused or unfocused ultrasound energy to at least one location in the object or subject at which shear waves are present Mechanical properties are then calculated from the acquired measurement data.

A transducer assembly for use in determining a health state of a joint (45) between first and second joined parts (42, 44); the transducer assembly comprising a transducer module (50) comprising a transducer element (100) for transmitting or receiving an ultrasonic signal to or from, respectively, the joint, and a mounting part (52) comprising an internal wedge portion (70), formed integrally with the mounting part (52), to which the transducer element (100) is fixed permanently so that the transducer module forms a unitary replaceable module.

Systems and methods for performing shear wave elastography using push and/or detection ultrasound beams that are generated by subsets of the available number of transducer elements in an ultrasound transducer. These techniques provide several advantages over currently available approaches to shear wave elastography, including the ability to use a standard, low frame rate ultrasound imaging system and the ability to measure shear wave speed throughout the entire field-of-view rather than only those regions where the push beams are not generated.

An electro-magnetic acoustic transducer (EMAT) having an electromagnet array is provided. The electromagnet array includes electromagnets. Each electromagnet includes a magnetic core and a wound coil wrapped around the magnetic core. The electromagnet array generates bias magnetic fields having different patterns when the wound coils are energized differently. For instance, the electromagnet array generates a bias magnetic field having a given pattern, for the EMAT to transmit a first type of ultrasonic wave such as shear-horizontal wave, when the wound coils are energized in a given manner; and generates a bias magnetic field having a different pattern, for the EMAT to transmit a second type of ultrasonic wave such as a Lamb wave, when the wound coils are energized in a different manner.