In order to solve the problem of difficult dynamic calculation and post-processing caused by complex irregular casing of large number of model elements and high order of the original matrix

a high-precision dynamic modeling and evaluation method for complex irregular casing based on experimental modal analysis-large-scale finite element-substructure condensation was proposed. Taking the main casing of a helicopter as the research object

the original finite element model of the special-shaped component was established and the validity of the model was verified through modal experiments. By analyzing the retained models of each mode of the substructure

the larger vibration energy space was selected as the condensed node

and then a condensation model with a greatly reduced number of degrees of freedom was obtained. The consistency of each mode before and after the condensation was verified by comparison. A method for measuring the model condensation error based on the correlation coefficient of the sequence was proposed. Finally

by taking the interface displacement compatibility condition into consideration

the substructure coupling was carried out; in addition

the inherent characteristics and computational efficiency of the overall model were compared. The research results showed that the dynamic characteristics of the condensation matrix were very close to the original matrix of the finite element

both the natural frequency and the mode error were less than 4%

the calculation time was shorter and the storage space was less occupied

greatly improving the calculation efficiency.