Versuchszeit-Reduzierung bei der mehraxialen Betriebslastensimulation durch das LBF Simultanverfahren

Investigations concerning the fatigue behaviour of components and structures are more and more based on multiaxial fatigue tests. Drive signals for service-like multiaxial tests are normally taken from actual service measurements, but real-time tests, with measured load-time histories, take much time and cause high costs. Consequently, the shortening, and acceleration of the fatigue tests is an important issue. For tests with test rigs and components which can be regarded as stiff for all practical purposes the 'Simultaneous Procedure' offers a solution to generate multiaxial drive signals similar to the well-known solutions applied for uniaxial drive signals: omission of small load cycles which are not fatigue-relevant and, "frequency-adapted"control of the drive signal. The "Simultaneous-Procedure" has been successfully applied to several multiaxial fatigue tests. Based on this experience the following advantages have been shown: A substantial reduction of testing time is achieveable . The acceleration factor depends, of course, on the density of the original load-time histories and the limits of the actual testing equipment The fatigue life and the crack initiation locations in tests with original and shortened load-time histories are equivalent. A steady exploitation of the test rig capacity and an improved accuracy by reducing crucial slopes is reached.