Research On The Frequency Calculation Formula Of Single Plate And Continuous Plate

In engineering application, the vibration problem of rectangular plate structure has been one of the most basic research subjects For hull, the each plate structure are subject to around the board structure and the reinforced constraint, equivalent to constrained by elastic boundary conditions, and hull plate structure of the boundary conditions is ranged from four sides of the rigid fixed and simply supported on four sides.In order to study the actual vibration of the hull plate and to predict its natural frequency, two models are studied in this paper. First model is a x b plate lattice model and the boundary conditions are divided into four edges simply supported and quadrilateral rigid fixed two forms; second model is 3a x 3b grillage model, focuses on the vibration of then middle plate, the plates around it and the reinforced bar are considered as the boundary conditions of the middle plate. And the boundary condition of the plate frame is rigid fixation.For the quadrilateral rigid fixed plates or rectangular plates with all edges simply supported boundary conditions, there are many formula that can be used to calculate the natural frequency, such as army formula, the ship structural mechanics handbook formula, the vibration of. foundation and practical calculation formula, Lloyd's formula and so on. The analytical solution of the natural frequency of the plate structure is given based on the corresponding theory. These formulas can be used for reference in predicting the frequency of plate structure. But the results of these formulas are not quite the same, there is a certain deviation. Different results cause some troubles for the prediction of the vibration of structures. So it is necessary to compare and analyze the calculation results of the formula to find the most appropriate formula to predict the structure of vibration.Due to the formula results in the comparative analysis, there is no uniform standard. Therefore, we use ANSYS software frequency results as a baseline, other formula calculation results were compared with ANSYS result, in order to find suitable weighting factors to realize the conversion between the formula and ANSYS calculation results and the mutual conversion between the formula calculation resultsThrough the research and comparison of each formula, and using ANSYS results as a benchmark to do the normalization processing, we realize the unification in the form of a weighting factor. This provides convenience for the prediction of vibration frequency.For the second kind of plate lattice model, the paper studies two unique reinforcing methods of this ship, to get a regular conclusion and find the appropriate correction factor through research and analysis. Through this way, I correct the results of the existing formula to the actual value of the frequency to achieve vibration prediction...