Study Of The Modeling Methods By Using Multi-Type Elements

In finite element analysis (FEA), solid model is often used. In order to obtain moreaccurate simulation results, it Mesh refinement method is often employed to analyze themodels, and the mesh density should be much higher, so that might cost muchcomputational time. Moreover, with the increasing number of elements, the cumulativeerror will increase. In order to improve the method, an alternative one of usingmulti-type elements modeling is presented, the solid models are equivalent to themulti-type elements models; which can ensure the accuracy,effectively reduce thenumber of elements in analysis and improve the quality of elements.In this thesis, the completion of the work content:1. First of all, the two modeling methods of using multi-type elements have beenresearched: direct modeling method and model importing method. Direct modelingmethod is modeling directly in WORKBENCH using multi-type elements, modelimporting method uses models established in other software (such as UG NX, PRO/Eect.), and import the models into WORKBENCH to processing to obtain models whichcan use multi-type elements. Secondly, a missile-borne DC power source has processedusing the method of model importing method to obtain multi-type elements model.2. Methods of connection between the different elements types have studied.Different connection methods solve problems between different elements ofdiscontinuous deformation stress uncoordinated; examples are tested, and the resultsshow that the errors between the results of the various connection methods are small,therefore, the methods of connection can be chosen on the basis of actual situationwhich method of connection is achieved easier.3. The equivalent models of power modules of the missile-borne DC power sourcehave established and are used for modal analysis and compared with the result of modalexperiment. In the first place, the equivalent plant-shell models of the power moduleshave established by using multi-type elements and used for modal analysis. In thesecond place, the solid models as a traditional method are used for modal analysis.Finally, the experimental results verify that results of the two analytical methods. Compared with experimental results show that: the results of the analysis of these twomodeling methods compared with the experimental results, the errors are small, but thenumber of elements of the equivalent models’ analysis needed is only one third of thatof solid models’, while the quality of mesh has a greater increase than the later method.In summary, a missile-borne DC power as the object of study, a new modelingmethod of multi-type elements has established. The method is not only reduced thenumber of model mesh, and improved the quality of meshing to some extent with acertain value in application compared with the traditional solid modeling methods.