Correction Criteria of Finite Element Modeling in Structural Dynamics

Abstract

In structural dynamics, analytical models based on the finite element method are often inaccurate for complex systems. Corrections are then made by using experimental data as standard references. Due to a lack of reliable criteria to measure the effectiveness of corrections, most of the available model correction methods are empirical in nature. In this paper, we carry out a comprehensive evaluation of model corrections by incorporating both analytical properties and numerical criteria. It is shown that, in many correction procedures, neglecting the correct correspondence between the system's natural frequencies and the eigenvalues of the stiffness matrix often misleads the model corrections. A correspondence rule of complex damping ratio is then proposed to avoid this problem. Several improved model correction methods are discussed.