Non-destructive testing by ultrasounds has been widely used to characterize cementitious materials. Ultrasonic techniques allow estimating mechanical properties of these materials by measuring both velocity and attenuation of the propagating ultrasonic pulse. In this study, both content and size of aggregates in mortar specimens are estimated by taking into account an optimization formulation w...

The condition of the surface through which a sound beam enters a material is an important factor in ultrasonic non-destructive testing(1). Detection of discontinuities such as cracks, voids and porosities in castings is greatly affected by the extent of roughness. Increased roughness reduces the transmitted energy of the sound beam and this, in turn, reduces the amplitude of the received signal...

Spatial variability of concrete is an important characteristic, which qualifies the non-homogeneity of concrete properties within structural components. Assessing it can be of great interest for damaged areas localization and for reliability analysis of structures. A two-stage experimental program was carried out using non-destructive testing (NDT) on laboratory concrete slabs in outdoor enviro...

Investment cast aerospace components are prone to defects related to solidification process. The hollow columnar-grained aero engine Vane casting, being discussed in this paper, suffers further from extraneous defects such as inclusions, core shift and resultant dimensional deviations. Due to its design complexity and stringent specifications, non-destructive evaluation (NDE) of this component ...

It is well known that in the Non Destructive Testing/Evaluation (NDT/E) context, Ultrasonic Echoes (UEs) and Tests (UTs) are intensively exploited to identify and characterize defects in the Carbon Fiber Reinforced Polymer (CFRP). This paper examines the localization and the classification of defects in this material from a fuzzy geometrical point of view. In particular, starting from an experi...

Maximum nongaussianity principle for ultrasonic flaw detection Hua-ming LEI, Wei LIANG, Pei-wen QUE Department of Instrument Science and Engineering, Shanghai Jiaotong University, Shanghai, 200240, P.R.China E-mail: [email protected] Abstract: The noise suppression techniques with wavelet transform (WT) are widely used in non-destructive testing and evaluation (NDT&E). In this paper, we have an...

The progressive development of civil engineering has forced scientists to improve the known methods and techniques testing building materials, also search for new ones, e.g., non-destructive (NDT) [...]