Development of Non-dimensional Dynamic Influence Function Method Based on Three-domain Decomposition Approach for Eigenvalue Extraction over Entire Frequency Range of Concave Membranes: Part 2(Example Studies and Discussion)

This paper is a continuation of Part 1, in which the Non-dimensional Dynamic Influence Function (NDIF) method based on a three-domain decomposition approach was theoretically formulated to enable accurate eigenvalue extraction over the entire frequency range, from lower-order to higher-order modes. This study (Part 2) applied the proposed method to concave membranes with complex geometries to verify its validity and accuracy. Two representative models were considered: an L-shaped concave membrane and a crown-shaped membrane with two concave regions. Using the method developed in Part 1, eigenvalues over the entire frequency range were successfully extracted for both models and verified through comparison with the results obtained using the finite element method (FEM). It was confirmed that the proposed NDIF method can accurately extract eigenvalues over the entire frequency range regardless of the number of boundary nodes, and achieve the same high level of accuracy as FEM, which requires significantly more nodes.