A Hybrid Static and Dynamic Model Updating Technique for Structures Exhibiting Geometric Nonlinearity

Finite element methods (FEM) are commonly used to analyze the behavior of various dynamic systems. Several model updating techniques are available that can be used for linear or nonlinear dynamic systems and help reduce discrepancies between characteristics obtained from the FE models and their experimental counterparts. Linear model updating techniques employ eigen solutions or the frequency response functions (FRF) to reduce errors between the discretized mass [M], damping [C], and stiffness [K] terms or FRF terms directly. However, model updating of structures exhibiting nonlinear behavior is seldom straightforward and requires special consideration of various terms contributing to the nonlinear responses when modeling the system. This paper investigates a hybrid static and dynamic model updating technique for structures exhibiting geometric nonlinearity. The static model updating minimizes errors in stiffness modeling and the dynamic model updating minimizes errors in modeling non-stiffness terms of the FE model.