Torsionsermüdungsprüfmaschine mit AC-Servomotor

Abstract

A Torsional Fatigue Testing Machine Based on a Commercial AC Servo- Actuator. In the present paper a recently developed torsional fatigue testing machine is presented. By the usage of a commercial AC servo-actuator as the loading unit, the testing machine could be realized at quite low expenses compared to servohydraulic torsional fatigue testing facilities. The servo-actuator, in which a precision angle counter is integrated, is controlled by the respective servo-amplifier. The torsional moment is measured with a standard torsion load cell. The generation of the command values, the acquisition and evaluation of the test data as well as the control of the test sequence are done by a PC that is equipped with a software package, which was particularly developed for this purpose, and an I/O interface, respectively. Additionally, an operational monitoring system was developed in order to prevent the occurance of unacceptable values of the torsion angle or moment, respectively. A bellows with a high stiffness under torsional loading is used for the connection between the load cell and the fixture of the specimen. This assures that neither longitudinal nor bending forces are acting on the specimen. Additional to a detailed description of the testing equipment itself, results of torsional fatigue tests on a ferritic-pearlitic railway steel are shown and discussed in this contribution.