Non-contact ultrasonic, enables rapid testing of structures using ultrasonic tests that are not possible via conventional contact transducers. This paper reports on laser ultrasonic and air/gas coupled ultrasonic measurements that are performed remotely, do not require direct access to test area, do not need traditional ultrasonic coupling and do not have traditional C-scan fixture requirements...

Structural health monitoring (SHM) systems operate online and test different materials using ultrasonic guided waves and piezoelectric smart materials. These systems are permanently installed on the structures and display information on the monitor screen. The user informs the engineers of the existing damage after observing signal loss which appears after damage is caused. In this paper health...

Carbon fiber laminate composites, consisting of layers of polymer matrix reinforced with high strength carbon fibers, are increasingly employed for aerospace structures. They offer advantages for aerospace applications, e.g., good strength to weight ratio. However, impact during the operation and servicing of the aircraft can lead to barely visible and difficult to detect damage. Depending on t...

Ultrasonic guided waves have been extensively applied for non-destructive testing of plate-like structures particularly pipes in past two decades. In this regard, if a structure has a simple geometry, obtained guided waves' signals are easy to explain. However, any small degree of complexity in the geometry such as contacting with other materials may cause an extra amount of complication in the...

Research into ultrasonic guided wave non-destructive testing for the long range inspection of large metallic structures is now well advanced. The main advantage of this method is that a large area can be covered from a given transducer position, so avoiding expensive scanning of all the structure surface. However, in the presence of attenuative coatings the test range can be dramatically reduce...

A prototype wireless guided wave inspection system is developed to inspect layered structures such as aircraft wing. The system includes a stationary antenna and an active antenna as transceivers, an on-board antenna as transponder, and PVDF comb transducers for generating and receiving ultrasonic Lamb waves. Preliminary experiments on a 0.8mm aluminium plate with a 12mm long, 50% through-wall-...

Multi-wire ropes are widely used as load-carrying constructional elements in bridges, cranes, elevators, etc. Structural integrity of such ropes can be inspected by using non-destructive ultrasonic techniques. The objective of this work was to investigate propagation of ultrasonic guided waves (UGW) along composite multi-wire ropes in the cases of various types of acoustic contacts between neig...

A novel technique for the measurement of Elastic Moduli of materials as well as measurement of temperature gradients using ultrasonic waveguides is described here. The range of temperature measurement was from room temperature to maximum utility temperature of waveguides or maximum measurable value of thermocouple temperature, typically beyond 1000°C. In this work, thermocouple wires have been ...

Due to adverse environmental conditions corrosion can develop during the life cycle of industrial structures, e.g., offshore oil platforms, ships, and desalination plants. Both pitting corrosion and generalized corrosion leading to wall thickness loss can cause the degradation of the integrity and load bearing capacity of the structure. Structural health monitoring of corrosion damage in diffic...

Besides the phase and group velocities, the amplitude of guided wave mode is also frequency dependent. This amplitude dispersion also influences the performance of guided wave methods in nondestructive evaluation (NDE) and structural health monitoring (SHM). In this paper, the effects of amplitude dispersion to the spectrum and waveform of a propagating wave-packet are investigated. It is shown...