制振材料を付加した三次元構造物の減衰特性解析 : 二層形積層制振構造の場合

抄録

We propose an efficient method for calculating damping characteristics of 3-dimensional 2-layer damped structure containing viscoelastic materials to save computation time, by using single layer finite element model for only metal structure and normalized strain energy of out-of-plane and in-plane deformation. In this proposed method, iterative calculation of eigenvalue analysis in full size matrix can be neglected and matrix size of the eigenvalue analysis is smaller than taht of the conventional modal strain energy method which uses 2-layer finite element model. Also, when thickness or location of the added viscoelastic materials is changed, we do not have to carry out eigenvalue analysis again. Furthermore, from the calculated results of normalized strain energy, we can estimate approximate tendency of effect of viscoelastic materials on damping characteristics of the 3-dimensional structure. This proposed method is applied to simple 3-dimensional 2-layer damped structure and calculation results are compared with experimental data and calculated results by using complex eigenvalue analysis and conventional modal strain energy method. Calculated results by the proposed method agree considerably well concerning loss factor and natural frequency.