An on-line correction technique of random loading with a real-time signal processor for a laboratory fatigue test

The authors present an application of the Solartron 1200 Real Time Signal P rocessor to correcting the on-line random loading in a fatigue test system. By inputting a power spectrum described by a data die to a computer, its c orresponding random process may be simulated. Since the processor is connec ted with a computer, results of signal processing done by the processor are sent to the computer periodically during the test. The computer performs p attern matching using the correlation coefficient value (CCV) between a loa ding spectrum and its predetermined target. If a CCV exceeds its threshold, the old data file will be replaced with a new one and the random loading e xerted on a specimen will be updated. When the new data file is obtained ba sed on optimal control strategy, the updated loading spectrum will approach its target. Therefore, an electrohydraulic fatigue test system equipped wi th a real-time signal processor can realize an on-line correction of a rand om loading based on the target spectrum desired. Since this updating does n ot change the original software package and hardware of the system, the per formance of the system and testing quality are safely improved.