| Title |
Analysis of the Natural Frequencies for Composite Laminated Plates with Multiple Attached Masses |
| DOI |
https://doi.org/10.12652/Ksce.2025.45.6.0601 |
| Keywords |
다중첨가질량; 복합적층판; 고유진동수; 특별직교이방성 Multiple attached mass; Composite laminated plate; Natural frequency; Special orthotropic |
| Abstract |
This study analyzes the variation in the natural frequency of a simply supported composite laminated plate with multiple attached masses. Reflecting practical conditions in civil engineering applications?where composite laminated plates are often subjected to external loads and additional masses?the deflection influence coefficient method proposed by Kim was extended to account for self-weight and arbitrary multiple attached masses. The analysis target was a specially orthotropic laminated plate that exhibits quasi-isotropic behavior as the number of layers increases, with all plies assumed to have the material properties of glass fiber reinforced plastic. Numerical analyses were conducted for two cases: (1) a single attached mass applied at each of the 25 points obtained by dividing the plate into a 5×5 grid, with the mass magnitude set as N times the plate’s self-weight, and (2) one attached mass fixed at the center (3,3) while the position and magnitude of a second mass were varied to compare the natural frequencies. The first-mode natural frequency was calculated through iterative computation combining influence coefficients with deflection-based resonance conditions.
The results indicate that the natural frequency decreases significantly as the attached mass increases in magnitude and approaches the plate center, and that masses placed at symmetric positions relative to the center yield similar trends. Furthermore, the extended Kim method was found to be a simple and effective approach for predicting natural frequencies in the presence of multiple attached masses. The findings of this study provide useful reference data for determining the placement and magnitude of attached masses in the vibration analysis and design of composite laminated plate structures. |