Abstract:There has been an increase in the use of composite materials in the aerospace industry which is driving a need for new NDT techniques that can rapidly scan large structures and provide quantitative data on the material integrity. In many applications there are common requirements for the ultrasonic inspection of composites for porosity, delaminations, foreign body contamination and fibre wrinkling. Traditional methods of ultrasonic inspection require the use of a single point probe or a multiplexed group of probes. NDT Solutions have developed new inspection techniques based on ultrasonic arrays housed within a rubber coupled wheel sensor. The wheel can be manually applied or scanned over the structure with an automated scanning system.Applications for the technology include real time imaging and reporting of impact damage, porosity sizing, delaminations and fibre wrinkles. Examples and case studies from a range of aerospace applications are given including manual and automated inspection of small and large area composites. Introduction:In recent years the number of applications for phased array inspection has increased dramatically, with many applications for weld and crack detection. Most of the applications utilise a sector scan or a B-scan raster mode to enable imaging of the defect as shown in figure 1.

The properties of thin layers of materials can be different from those in the bulk form. The response of a coating to any given load and its ability to remain bonded to the substrate will depend on its elastic modulus and Poisson's ratio. In this study a measurement method based on ultrasonic bulk wave reflection was evaluated. As a model system, a thin layer of polyethylene was pressed between two solid steel bodies. The reflection spectra of longitudinal and shear ultrasonic waves were recorded from the coating. The frequencies at which the layer resonates were measured and from this the wave speeds deduced. The Poisson's ratio can be determined from these two wave speeds and if the layer thickness is known the modulus is also available. The tests yielded reasonable values for both. This approach is only suitable if the layer can be made to resonate by the available ultrasonic frequencies; typically this will be the case for thicker coatings (tens of microns). Further, good coupling between the layer material and the steel bodies is necessary so that the interfaces do not themselves act to reflect ultrasound. This is better achieved with a smooth soft coating.

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Ultrasonic and electromagnetic inspections of railway hollow axles Ultradźwiękowa i elektromagnetyczna inspekcja kolejowych osi drążonych tomasz Chady, rzegorz Ps j-Zachodniopomorski Uniwersytet Technologiczny, Szczecin, imosthenis Liaptsis, Sta ros a ramidis-TWI, I an Castro, Kenneth Lobato-Ideko, Nei ankinson, Chris regory-Phoenix, Ignacio garte azpiri-Danobat Railway Systems Introd ction The structural integrity of wheelsets used in rolling stock is of great importance to the rail industry and its customers. In the last 15 years, 33 deaths and 48 injuries have occurred in Europe alone because of train axles failures. This is not to mention the financial aspect