Dynamics model updating of an offshore platform structure based on optimized Kriging model

A dynamics model updating method combining the Kriging model with the multi-scale objective genetic algorithm(MOGA) optimization for the experimental model of an offshore platform structure was proposed. The modal frequencies were set as updating targets, and the Kriging model between updating parameters and modal frequencies of the platform was set up and, in replacement of the commonly used finite element model, applied to the model updating. In order to solve the problem that approximate error may cause a disturbance to the updating result, the method of MOGA based on an infill-sampling optimization approach was provided. Model tests of the offshore platform model in the lab based on hammer excitation were employed to prove the effectiveness of the method. The results show that the Kriging model can effectively reveal the complex mapping relations between the updating parameters and modal frequencies, and the infill-sampling criteria provided can significantly improve the precision of the Kriging model, which can be applied in actual engineering. © 2019, Editorial Office of Journal of Vibration and Shock. All right reserved.