| Dynamic testing and analysis are very essential to vibration reduction and control. Dynamictesting is an important and ultimate way in determination of dynamic characteristic of a structure.Validity of the analytical method and accuracy of the simulation results can be verified by testing data.In addition to those mentioned above, dynamic behavior of the structure under realistic vibrationenvironment can be restored through dynamic test too. However, power of the testing devices havetheir own limitations, this makes it difficult to use current testing device carrying out experiments tosome huge structures, such as an entire big airplane. Just for these reasons, scaled model based ondynamics similarity relationship was used as the test model when carry out dynamic experimentsinstead of the real one.This paper was mainly focused on applications of the similarity theory in dynamic experiment.Based on similarity theories, mode similarity of the scaled modal and the real one were determined.Thin plate which had non-proportional geometric factors along each direction was taken as a typicalexample to illustrate validity of mode similarity of the scaled modal. Mode test and numericalsimulation results both show that modes of the scaled model predicted by similarity relationshipproposed in this paper had good agreement with the modes of the full-scaled thin plate. In addition,the time-domain response correction method of the non-similar damping dynamic model is studiedand is simulated with finite element numerical method.At last, the similar dynamics finite element model updating problem is also studied. The dampingmatrix of the finite element model is correcting based on the matrix correction method of thefrequency response function. The correction method through the simulation and sheet structurevibration test data is validated. The results are showing that amended theoretical model tallies wellwith the test model, and meets the requirements of practical engineering applications. |
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