The detection of defects in aerospace structures with nondestructive techniques is an important requirement for quality checks not only during production phase but mainly during in-service maintenance operations. Visual inspection allows only the analysis of surface characteristics of materials. For subsurface defects like corrosion or cracks a deeper analysis is required. For aerospace structures are mainly used two different approaches. The first method is based on induction of currents in tested electrically conducting material also known as Eddy Current inspection. Changes in electromagnetic field are used by signal analysis system to identify or differentiate between wide variety of physical, structural and metallurgical characteristics of the tested material. The second method uses high frequency sound waves which are sent into the object under the test. A probe picks up the reflected waves and an analysis of received signal is done to locate flaws in the tested object. Ultrasonic inspection can detect defects such as cracks and discontinuities.

In this paper, we address the problem of different detection performances of nondestructive inspection methods using comparison of several industrial and experimental probes. We designed 4 different eddy current probes. We made an analysis of coil and GMR sensor and we tested this design on Dural plate used a part of standard airframe. We used two different data acquisition systems. After that we evaluated this sample with certified industrial Eddy Current system. We propose to use new experimental Electromagnetic Acoustic Transducer (EMAT) probe with multidimensional signal processing. Same as in case of experimental Eddy Current system we verified final analyses with industrial piezoelectric ultrasonic transducers.

The paper deals with the modern nondestructive elasticwave testing of concrete in foundation slab in a very important office building put under the ground water level. After the construction water has appeared in lower level of the building. The reason for the tests was to find the place where water gets for building, and also check the technical condition of the foundation slab to take a decision about the range of repairs to be done to the foundation slab or about their strengthening.

Corrosion is one of the industries major issues regarding the integrity of assets. Currently inspections are conducted at regular intervals to ensure a sufficient integrity level of these assets. Both economical and social requirements are pushing the industry to even higher levels of availability, reliability and safety of installations. The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections reducing uncertainty and extending inspection intervals. Guided wave travel time tomography is a promising method to monitor the wall thickness quantitatively over large areas. Obviously the robustness and reliability of such a monitoring system is of paramount importance. Laboratory experiments have been carried out on a 10 pipe with a nominal wall thickness of 8 mm. Multiple, inline defects have been created with a realistic morphology. The depth of the defects was increased stepwise from 0.5 mm to 2 mm. Additionally the influences of the presence of liquid inside the pipe and surface roughness have been evaluated as well. Experimental results show that this method is capable of providing quantitative wall thickness information over a distance of 4 meter, with a sufficient accuracy such that results can be used for trending. The method has no problems imaging multiple defects.