Research And Implementation Of FRF-based Substructure Hybrid Modeling

In the dynamics analysis of large and complex assembly structure, using dynamicsubstructure method can effectively reduce the scale of calculation or testing. Usingtheoretical model and test model of substructures to get dynamics of the integrated structurehas broad prospects in engineering applications. Existing modal synthesis methods havemodal truncation errors, and have many difficulties in handling of the test substructure. Thefrequency response function(FRF) matrix of structure can contain all of the modalinformation, which can get more accurate synthesis results. Based on the above considerations,the FRF-based substructure(FBS) method was used to realize the solution of hybrid modeling.The main contents in this dissertation are as follows:Critical theory of FRF-based substructure hybrid modeling was studied. The calculationprinciple of FRF in substructure and the method of building connection model wereintroduced. Based on previous FRF synthesis method in rigid connection conditon, flexibleconnection was presented into account and a method of FRF synthesis considering connecionproperty was derived, during which the general treatment of rigid connection and flexibleconnection was realized.The solution system of FRF-base substructure hybrid modeling was developed. Thesystem modules and object-oriented data structure were designed and the key algorithmsduring implementation of the system were analyzed. The framework of MKL based FRFsynthesis solution was bulit, which can deal with multi-substructure and different connectionproperty.The results of this system were verified through practical examples and compared withthe hybrid modeling results of LMS Virtual Lab, which proved the effectiveness of thissystem.Some problems to be further studied were put forward in the end of this dissertation.