The Fraunhofer Institute for Nondestructive Testing IZFP carries out research and development activities in the field of nondestructive testing processes along the entire materials value chain. For customers in the automobile, aerospace, rail, energy, construction and agriculture industries, the institute offers a wide range of NDT expertise and technologies. At the 19th World Conference on Non-Destructive Testing, our engineers will be presenting the acoustic resonance testing (ART) - an integral nondestructive testing method that is used to inspect components and assemblies with regard to different properties or variations in quality.
Acoustic resonance testing (ART) is an integral nondestructive testing method that is used to inspect components and assemblies with regard to different properties or variations in quality by evaluating the test object’s eigenfrequencies or other parameters determined from its natural vibration behavior.
As a comparative method, ART mainly focusses on the examination of serial parts which are produced in large quantities and with low cycle times, e.g. forged or casted metallic parts. Besides the possibility for complete automation, a big advantage of ART compared to other volume-oriented methods is the fast in-line quality assessment of an entire specimen within a matter of seconds.
The principle of ART is based on the fact that a specimen’s natural vibration behavior and its eigenfrequencies mainly depend on geometry and material properties, but also on structural defects, e.g. cracks.
One objective of ART is to detect defective parts by evaluating the test object’s measured eigenfrequencies. Generally, the exact geometric dimensions and the exact material properties of single parts in a serial production vary randomly within acceptable ranges, for example because of manufacture-related effects, entailing variations in the eigenfrequencies of the good parts.
These effects are superposed by changes in the eigenfrequencies caused by intolerable component variations. This impedes a reliable classification of the components with the help of ART. To solve this problem a new compensation method of those random perturbations respectively a method to differ between eigenfrequency shifts caused by acceptable as well as intolerable variations is required.
A current research project focusses on detecting forged or casted metallic parts with intolerable geometric variations by evaluating the component’s eigenfrequencies, whereat such parts are also characterized by large acceptable component variations.
Previous investigations using simulated data showed that the exact dimensions of components can be estimated from their eigenfrequencies after describing those correlations with the help of linear regression analyses. This contribution presents the latest results of the project, especially the adjustment of this procedure to real parts and the associated difficulties.
Sabine Poitevin-Burbes | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP
ADIR Project: Lasers Recover Valuable Materials
21.07.2017 | Fraunhofer-Institut für Lasertechnik ILT
High-tech sensing illuminates concrete stress testing
20.07.2017 | University of Leeds
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
21.07.2017 | Earth Sciences
21.07.2017 | Power and Electrical Engineering
21.07.2017 | Physics and Astronomy