An innovative approach for bias correction of a passive controlled offshore structure using experimental non-contact measurements

The discrepancy between the theoretical and experimental results is defined as one of the main reasons for updating the analytical models of the structures based on experimental data sets. Although various updating methods have been proposed in the literature, the capability of the approaches on controlled systems is yet to be investigated. In this paper, a numerical model updating method is proposed considering both parametric and structural uncertainties on a passive controlled complex structural system. The method is applied on a three-dimensional offshore jacket platform model including an attached Tuned Liquid Column Gas Damper (TLCGD) damping system. The effect of the damper parameters on updating the numerical model is investigated for the first time using a Laser Doppler Vibrometer (LDV) as a non-contact measuring system. The maximum decrement is occurred using a sine function which seems to be because of the sinusoidal nature of the experimental data. According to the results, the discrepancy between the numerical and experimental data can be decreased by 75 percent utilizing non-contact measurements and discrepancy functions. The results also indicate that by calibrating the gas pressure and the total liquid column length of the TLCGD damping system, as the most important parameters of the damper, the discrepancy is decreased almost 66 percent. The proposed method of updating the FE model for the controlled systems is beneficial for the old sophisticated controlled practical systems that increasing their life time span is essential.

Automated summary

The paper proposes a numerical model updating method considering both parametric and structural uncertainties on a passive controlled complex structural system. By calibrating the gas pressure and the total liquid column length of the TLCGD damping system, the discrepancy between the numerical and experimental data can be significantly decreased.