Theoretical Prediction and Experimental Verification of Optimum Exciter Configurations for Modal Testing.

Kurzfassung

Although much progress has been achieved in the predictive capa- bilities of modern finite element codes in structural dynamics, experimental investigations are necessary to validate and to update the respective mathematical model. The reliability of the measured data in modal testing depends significantly on the applied exciter locations and force distribution. Advanced knowledge of optimum exciter configurations could increase the measuring capacity and reduce test time. Based on the results of a pre-test finite element analysis, an algorithm aimed at the optimization of the exciter locations and force appropriation for phase resonance modal testing has been developed, availing itself of a genetic algorithm procedure.In numerical tests this optimization algorithm has shown its potential both in finding the optimal force appropriation and in minimizing the number of strictly necessary exciters. To verify the capabilities of this algorithm, experimental studies were performed on actual test cases. The predicted optimum exciter configurations were applied and compared with the results of a modal survey test. The present paper describes the theoretical and experimental investigations and correlates to the respective test results. The advantages of the approach are reviewed and improvements from experimental requirements are suggested.