Harmonic response calculation of viscoelastic structures using classical normal modes: An iterative method

An efficient iterative method, which only requires normal modes, is presented to calculate the harmonic response of viscoelastic structures. The method only needs to iteratively solve a diagonal dynamic equation instead of solving the dynamic equation directly such that it takes O(N2) instead of O(N3). However, the iterative procedure based on lower normal modes cannot be converged to the exact result. A modal correction technique is therefore introduced to improve the accuracy of iterative results. Finally, the efficiency and applicability of the method are illustrated in terms of sandwich plates with different types of viscoelastic core.