Structural Dynamic Model Updating Of A Bolted Plate

This study mainly discusses structural dynamics model updating based sensitivity analysis, whichincludes the application of optimization techniques. The framework is presented in four parts: firstly,structure modal experiments are carried out which allowed obtaining the modal information usingparameter identification technology, the extracted information is then used as references for updatingthe corresponding numerical models; secondly, finite element modeling is conducted in thecommercial software and then model analysis is straight forward. With the aid of data processingprocedure in Matlab, extract the information of the element and node, which will be used in the nextpart.; thirdly, formulate the polycondensation model whose degree of freedom is the same as theexperimental model. Apply the residual force vector method to the obtained reduce model, estimatedthe parts, which should be modified, according to the residual force vector theory, and identify thecorrection parameters by employing sensitivity analyze; Fourthly, treat the model updating problemas an optimization problem. It is aimed to obtain a set of modified parameters, satisfying theminimum difference between the numerical modal and experimental modal, using genetic algorithmswith trust region Newton method. In the earlier study, parameters correction were conventionallyselected depend on work experience. However, the rapidly increasing complexity of the structure andmaterial parameters indicate the challenge of this work. As a result, the method of damage location isintroduced in the model modification by the author. And the results highlight the accuracy in theamendments of the parameters in the boundary conditions.In the experimental part, simulation of cantilever is first carried out, which demonstrates thefeasibility of the modal updating theory and amendment procedure. Moreover, procedure is alsoapplied to a clamped plate to modify its finite model. It is shown that the proposed method is wellcapable in positioning error of the multi boundary conditions and can provide a updated modal withinreasonable accuracy. Thus, this approach has a significant reference value in the industry.