Stress-dependent elastic moduli of polycrystalline materials are used in a statistically based model for the scattering of ultrasonic waves from randomly oriented grains that are members of a stressed polycrystal. The stress is assumed to be homogeneous and can be either residual or generated from external loads. The stress-dependent elastic properties are incorporated into the definition of th...

Vibrothermography, is an established NDT method praised for its fullfield and defect-selective imaging. Especially for cracks and similar damage, defect signals are produced within seconds for a wide variety of materials. Usually high power sonotrodes that are applied with kN pressure are employed in order to maximize ultrasonic excitation of the specimens. An increase in excitation power is us...

V. Aleksić, Institute for Testing Materials-IMS Institute , Belgrade, Serbia, M. Dojčinović, Lj. Milović, University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia, I. Samardžić, University of Osijek, Mechanical Engineering Faculty in Slavonski Brod, Croatia. This paper presents the research into behaviour of HSLA steel affected by cavitation. The parent material (PM) and s...

For more than 6 years, the automated ultrasonic and eddy-current systems for the inspection of railroad wheel sets, developed by Fraunhofer IZFP and Fraunhofer TEG, have been field-hardened through daily operation at various maintenance facilities of the Deutsche Bahn (DB). The testing stations are equipped with IZFP’s multi-channel electronics, a modular PC integrated system operating inside 1...

Objective Roughness is the main parameter in interlocking bonding mechanism. Yet there is no model designed to evaluate the effect of surface roughness on adhesion of coating materials in pharmaceutical sciences. Materials and Methods In this study polymethyl metacrylate spherical beads with different sizes were poured into 10 mm mold, then it was pressed by hand screw and finally heated to 141...

OBJECTIVE This study aimed to evaluate and compare the mechanical properties of five commercial core materials using fracture toughness (FT), Knoop hardness number (KHN), diametral tensile strength (DTS), and dynamic elastic moduli (DEM). METHODS Composite material specimens were produced (Rock Core, CosmeCore, ParaCore, MultiCore Flow, and Filtek Supreme Plus). The FT test (n = 15) was perfo...

This paper presents the development of inspection strategies dedicated to the quality insurance of the wind turbine blade manufacturing process and in particular the inspection of the adhesive bondlines. Ultrasonic testing is recognized as a technique that can provide valuable information about the structure. Porosity, dry area and delamination can be detected and characterized in laminates. La...

Ultrasonic cleaning of the RBFDP in ethanol for 10 min. The remnants of loose particles after air abrasion may impair wettability of the silane or the primer and the subsequently applied adhesive resin. Ultrasonic cleaning eliminates such remnants best.3 a Professor, University of Zürich, Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics a...

When detect the helicopter rotor beam with ultrasonic testing, it is difficult to realize the noise removing and quantitative testing. This paper used the wavelet analysis technique to remove the noise among the ultrasonic detection signal and highlight the signal feature of defect, then drew the curve of defect size and signal amplitude. Based on the relationship of defect size and signal ampl...