Nondestructive testing techniques have attracted growing interest in the last few years due to their ability assess material properties without damaging specimens. The free-free resonance method is a nondestructive technique based on analysis of natural frequencies sample. This study presents and discusses applicability this technique, traditionally used soils, for mechanical characterization r...

Local hardness increasing on the surface of the power plant rotor may result in severe damages. One major solution for rapid repairing of the rotors is the adaptive tempering heat treatment. For this purpose, after identification of the damaged rotor, initial investigations and tests (such as visual inspection, chemical analysis, nondestructive hardness measurements and replica or on-site metal...

Cement grouted soils, which consist of particulate soil media and cementation agents, have been widely used for the improvement of the strength and stiffness of weak ground and for the prevention of the leakage of ground water. The strength, elastic modulus, and Poisson's ratio of grouted soils have been determined by classical destructive methods. However, the performance of grouted soils depe...

The capability of embedded piezoelectric wafer active sensors (PWAS) to perform in-situ nondestructive evaluation (NDE) is explored. Theoretical developments and laboratory tests are used to prove that PWAS transducers can satisfactorily perform Lamb wave transmission and reception, pulse-echo, pitch-catch, and phased array functions of conventional ultrasonics thus opening the road for embedde...

In the present study EP142-C510-50 woven carbon fiber composite was investigated from structural/ mechanical point of view aiming manufacturing parts for aeronautical industry. The composites were obtained by hand lay-up process. Prior to mechanical tests, the cure reaction results of composite resins specimens were analyzed by using DSC technique. The EP142 epoxy matrix was cured/polymerized a...

This paper addresses the problem of leakage in water distribution systems through the use of ground penetrating radar (GPR) as a nondestructive method. Laboratory tests are performed to extract features of water leakage from the obtained GPR images. Moreover, a test in a real-world urban system under real conditions is performed. Feature extraction is performed by interpreting GPR images with t...

The capability of embedded piezoelectric wafer active sensors (PWAS) to perform in-situ nondestructive evaluation (NDE) is explored. Laboratory tests are used to prove that PWAS can satisfactorily perform Lamb wave transmission and reception. Subsequently, crack detection in an aircraft panel with the pulseecho method is illustrated. For large area scanning, a PWAS phased array is used to creat...