Carl Schenck Ag

Friedrich Klinger

Andreas Pohl

Guenter Keller

Guenter Zuber

Jan Brezina

Josef Beran

Gerhard Schimanski

Materials, or structural components are tested under resonance conditions by means of a pressure operated load mechanism controlled by a servo-hydraulic control unit. The pressure medium is part of the oscillating system. The spring rate or stiffness of the pressure medium is adjusted relative to the spring rate of the test sample, or rather relative to the spring rate of the entire oscillating system in such a manner that the maximum pressure occurring at resonance operation corresponds as close as possible to the rated supply pressure of the system. The load mechanism comprises a single cylinder for producing dynamic loads for the resonance operation and also static loads of substantially the same size as said dynamic loads.

Method and hydraulic testing apparatus for performing resonance tests

This hydraulic chucking head, especially for testing machines wherein the test sample must be held without play in the direction of load application, includes at least two test sample holding pistons movable along a common axis toward each other and toward a central axis through the chucking head. These pistons are hollow inside and movable in respective cylinders in the housing with a certain initial play. The piston walls or jackets are elastically yielding when the pressure inside the piston is increased, whereby the test sample is held and simultaneously said play is removed since the piston walls are pressed against the respective cylinder bores. Preferably a non-metallic coating is provided between the piston walls and the cylinder bores which coating acts as a sealing and reduces friction.

Hydraulic chucking head

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Garmisch Partenkirchen, Germany

Friedrich Klinger