Modified Interval Perturbation Finite Element Method for a Structural Acoustic System With Interval Parameters

Abstract

For the frequency response analysis of the structuralacoustic system with interval parameters, a modified interval perturbation finite element method (MIPFEM) is proposed. In the proposed method, the interval dynamic equilibrium equation of the uncertain structuralacoustic system is established. The interval structuralacoustic dynamic stiffness matrix and the interval force vector are expanded by using the firstorder Taylor series; the inversion of the invertible interval structuralacoustic dynamic stiffness matrix is approximated by employing a modified approximate intervalvalue Sherman–Morrison–Woodbury formula. The proposed method is implemented at an elementbyelement level in the finite element framework. Numerical results on a shell structuralacoustic system with interval parameters verify the accuracy and efficiency of the proposed method.