Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Wölfel Engineering Gmbh & Co. Kg.

Lars Schubert

Uwe Lieske

Bernd Frankenstein

Bianca Weihnacht

Tobias Gaul

Olaf Roeder

Frank Schubert

Bernd Koehler

Constanze Tschoepe

Eberhard Schulze

Herbert Friedmann

Fritz-Otto Henkel

Carsten Ebert

Constanze Tschöpe

Olaf RÖDER

Thomas Klesse

Robert Neubeck

Bernd KÖHLER

A method for non-destructive testing of walls of components, at least one ultrasonic transducer () which is fixed to a surface of the wall is used to emit horizontally polarized transverse waves () in a lateral propagation direction and compression waves or vertically polarized transverse waves () in a radial propagation direction. The at least one ultrasonic transducer () and/or at least one further ultrasonic transducer arranged at a known distance from the at least one ultrasonic transducer () on the respective wall of the component () is/are used to detect horizontally polarized transverse waves () reflected by defects and compression waves or vertically polarized transverse waves () after or while running the non-destructive testing of the wall in order to determine the respective wall thickness.

Method for non-destructive testing of walls of components

In the system, two ultrasonic transducers, which form a pair and each have a piezoelectric ceramic plate-shaped element with a rectangular geometry, can be fastened to a surface of a component. The two ultrasonic transducers are arranged at a distance from one another such that there is no direct mechanical contact and they are arranged beside one another with a parallel orientation of their central longitudinal axes. The two elements have a different polarization along their width and are connected with the same polarity to an electrical voltage source. The two plate-shaped elements can also have an identical polarization along their width and can be connected in this case with opposite polarity to an electrical voltage source. At least one ultrasonic transducer and/or at least one further ultrasonic transducer is/are designed to detect ultrasonic waves reflected by defects and/or shear waves simultaneously emitted by the two ultrasonic transducers.

System for the non-destructive testing of components

Embodiments of the present invention provide a device for obtaining information about one or more living beings. The device comprises an actuator, a sensor and an evaluator. The actuator is configured to output an excitation signal for exciting the living being(s). The sensor is configured to detect a signal generated by the living being(s) in reaction to the excitation signal, to obtain a detected signal. The evaluator is configured to evaluate the detected signal so as to obtain the information about the living being(s).

Device and method for obtaining information about one or more living beings

The invention relates to a method for monitoring the condition of rotor blades for wind turbines. It is therefore the object of the invention to increase the accuracy of the monitoring of the condition of rotor blades of wind turbines and to allow a localization of faults or defects and their exact description. In the method in accordance with the invention, eigenvibrations of a rotor blade occurring globally at the rotor blade and locally guided elastic waves are permanently detected with time and spatial resolution using a sensor network and actuator network attached to the rotor blade or using a network arrangement of ultrasound transducers. In addition, elastic waves which are guided periodically at predefinable time intervals and which are respectively emitted by an actuator or ultrasound transducer and detected by sensors or ultrasound transducers are in so doing inspected for variations of the emitted waves.

Model-based method for monitoring the condition of rotor blades

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Dresden, Germany

Lars Schubert