38. A Review of Critical Parameters Required for Accurate Model Updating of Geometrically Nonlinear Dynamic Systems

Model updating is an essential part of any dynamic system study. In an ideal situation, an experimental analysis and a corresponding modeling analysis must establish equivalent characteristics for the same dynamic system. This is a tall task, particularly for nonlinear systems where known parameters are surpassed by many unknown parameters crucial for establishing the right model. In contrast, many robust techniques and processes are available for model updating of linear vibration systems. However, the linear updated models typically provide erroneous characteristics when directly employed for nonlinear studies. In this paper, a test structure exhibiting geometric nonlinearity is experimentally studied, and the same is modeled using finite element method (FEM). A study of various parameters involved during the modeling processes such as any assumed parameters and boundary conditions is thoroughly reviewed. The deficiencies of linear model updating processes are highlighted, and suitable workarounds that provide more meaningful and well correlating models for nonlinear dynamic systems are discussed in this paper.