Experimental Modal Loss Identification And Its Frequency Estimation Method

The experimental modal analysis is an important method to study the dynamic characteristics of the structure.However,due to the irrational selection of the picking point or the excitation point in the testing process,there is a phenomenon that the experimental mode is lost.At present,in this paper,the following problems are studied in this paper:in this paper,we study the loss of test mode by using the experiment,(1)Based on the correlation matrix,the matching matrix between the modal and the experimental modality is constructed and the correlation matrix between the modal and the experimental modal is constructed.Matching matrix,and finally in accordance with the test mode loss identification rules to identify the loss of the test mode order.(2)The empirical model derives the frequency estimation theory to derive the correlation coefficient between the experimental modal frequency and the calculated modal frequency,and the non-lost computational modal frequency is used to obtain the lost experimental modal frequency estimate.And then the modal frequency estimate of the lost test is corrected based on the frequency deviation coefficient between the experimental modal frequency and the calculated modal frequency.(3)Design of modal loss identification and frequency estimation system design,using MATLAB GUI as system development platform,combined with ANSYS APDL parameterized design language and MATLAB command to develop test mode loss identification and frequency estimation system,the system can quickly and easily identify the lost test modal order and estimate the lost test mode frequency.(4)Through the example verification,with the simple support beam and the combination of simply supported beam as the test object,the experimental mode is obtained,combined with the experimental mode loss identification and its frequency estimation system,to identify the lost test mode,and estimate the lost test mode frequency.The results of the example show the correctness of the experimental mode loss identification and its frequency estimation theory,and the practicality of the experimental mode loss identification and its frequency estimation system.At the same time,the modal frequency estimation value is accurate.The loss of test mode has some guiding significance.