Finite Element Model Updating Based On Regularization Method

Accurate finite element model is the foundation of the engineering structuralanalysis. The real engineering structures are often influenced by the reasons such asthe simplification of model, the construction error, the environmental factors thatlead to the change of original design model, therefore it needs to use the finiteelement model updating technology and the experimentally measured data tomodify the finite element model. Finite element model updating problem hasbecome a focus and hot topic of current research.According to the different types of the test loading and the known responseinformation, we can divide into structural finite element model updating based ondynamic information (such as frequency, vibration mode and other information) andbased on the static information(such as the displacement, the strain and thecurvature information); with the model updating of different objects, the finiteelement model updating can usually be divided into matrix method and designparameter method; according to the algorithm and the selected parameters, modelupdating is divided into direct method and iterative method.This paper use the parameter updating method, and choose the elastic modulusE of the structure element which is very important to the accurate assessment ofstructural performance as the correction parameter. The main contents are asfollows:（1）Finite element model updating method based on the improved gradientregularization method and the strain test information is proposed.（2）Finite element model updating method based on the improved gradientregularization method and multiple conditions strain measurement information isproposed.（3）Finite element model updating method based on the improved gradientregularization method and dynamic test information is put forward.（4）Using Fortran language to write the general finite element analysis programof the above methods, and verified the above methods numerically. （5）Through the numerical simulation analysis and structural engineeringexample, we can draw the following conclusions:1）The gradient regularization—finite element model updating method based onstrain and frequency information are available.2）The gradient regularization algorithm has characteristic of fast convergencespeed, and high solution stability.3）According to the response information and previous engineering experiencein terms of theory, using static strain, displacement and other information have morestable model updating effect, and the anti-interference in the frequency slightlyreduced. So it is advised to ensure the reliability of the data and information as muchas possible when using frequency.