Dynamic characterization and optimization of pot bearings in bridges using finite element analysis

Bridge bearings are crucial components of the overall bridge structure. Among all the bearings used for bridges, pot bearings are a commonly used type of bridge bearing. Pot bearings support the bridge superstructure and allow it to move independently of the supporting elements, such as piers and abutments. Investigating the dynamic behavior of pot bearings is challenging due to the complexity of the bearing, which consists of several materials. It requires advanced modeling techniques that are typically expertise demanding, time consuming, and often proprietary to manufacturers. Therefore, this research aims to determine the dynamic properties of pot bearings, optimize their finite element (FE) models, and develop a reliable framework for assessing and enhancing the dynamic behavior of pot bearings under harmonic loading in bridge system. Experimental and FE modal analysis were employed to extract dynamic properties, while response surface method (RSM) and direct method optimization were used to refine material parameters, ensuring close agreement between numerical and experimental results. The optimized pot bearing model was subsequently integrated into harmonic response simulations to evaluate the bridge system’s dynamic performance using FE analysis. From the modal analysis, discrepancies between the FE and experimental results were identified, with relative errors of up to 43.9% observed in the natural frequencies, necessitating model refinement. Despite these discrepancies, the mode shapes exhibited good agreement between the two methods. To address these errors, the pot bearings were updated and optimized to achieve the best FE model that closely aligns with experimental results. Design parameters such as Young’s Modulus and Poisson’s Ratio were systematically adjusted to minimize discrepancies between FE and experimental results. The RSM approach outperformed the direct method, achieving significantly reduced relative errors. The total relative error was reduced from 43.9% to 8.42% using RSM, compared to 11.16% with the direct method. The optimized pot bearing model obtained through RSM was then used to evaluate its performance in a bridge application under harmonic loading conditions. The results showed that the bridge equipped with optimized pot bearings exhibited improved performance, with significantly reduced displacement at the bridge mid span compared to the bridge with non-optimized pot bearings. For all modes, the maximum deformation of the optimized bridge system was reduced by up to 17% compared to the non-optimized bearings. In conclusion, this study highlights the critical role of pot bearing optimization in improving the dynamic performance of bridge structures. A reliable framework for assessing and enhancing the dynamic behavior of pot bearings under harmonic loading was successfully developed through the integration of numerical simulations, experimental validation, and advanced optimization techniques. This framework provides a robust and efficient approach for accurately modeling and evaluating pot bearing performance, contributing to safer and more resilient bridge systems.