Modal Analysis Of Complicated Elastic Plate With Concentrated Mass

The complicated elastic plate with concentrated mass is widely used in the fields of mechanical engineering, electronic equipments, aerospace, etc. Its dynamic characteristics have significant effect on the reliability of the system. In order to ensure high reliability of the system, dynamic characteristics of the complicated elastic plate with concentrated mass must be studied deeply.In this paper, combining analytical modal analysis, finite element modal analysis with experimental modal analysis, dynamic characteristics of the complicated elastic plate with concentrated mass is analyzed as follows:Firstly, based on the theory of conformal mapping and the method of modern numerical value, with the help of trigonometric interpolation and normal convergence method, the conformal mapping function between complicated region and the unit dish region is gotten, thus a feasible analytical method can be provided for complex mission modeling. By Galerkin method, the fundamental frequency parameter of the complicated elastic plate is analyzed, determining the first modal frequency ranked for the experimental modal analysis.Secondly, according to the structural characteristics, boundary conditions, etc., the finite element model is created. Subsequently, numerical modal analysis is processed by MSC.MARC software. Comparing with the result of experimental modal analysis, it is indicated that the finite modeling method is reasonable.Finally, in experimental modal analysis, the testing method of the hammer multiple-inputs and single-output is applied and the testing platform is established. Taking the complicated elastic clamped plate with concentrated mass as an example, through the analysis of frequency response function, both the natural frequencies and mode shapes are realized by DASP (Data Acquisition and Signal Processing) modal analysis software. Comparing with the result of analytical modal analysis, the analytical method proved correct.In summary, through the analytical modal analysis, finite element modal analysis and experimental modal analysis, the dynamic characteristic parameters including natural frequencies, mode shapes and damping are gotten, which will be provided for further fault diagnose, reliability analysis and estimation, structure optimal design and dynamic model modification.