Mechanical Characteristics and Predictive Reliability of Spherical Hinge Scaling Model for Swivel Bridge Using Distortion Correction

ABSTRACT The spherical hinge, acting as a swivel bridge’s pivotal load-bearing element, undergoes a highly intricate stress distribution under high-pressure conditions, which poses significant challenges for precise field measurements and theoretical analyses. To tackle this problem, the current study formulates a model for indoor scaling distortions in the spherical hinge framework and presents a matching predictive approach to reliably capture its stress condition when subjected to high-pressure conditions. Initially, a similarity formula is derived and validated for various common types of spherical hinge structures, facilitating the determination of an optimal scale ratio for the indoor model. Subsequently, an indoor scaling distortion model is meticulously designed and constructed, taking into account the distortion effects arising from substantial scaling reductions. A corresponding prediction and correction method is also proposed to enhance the accuracy of the model. To validate the efficacy of these methods in predicting the scaling hinge structure’s mechanical behavior, an indoor simulation loading test is conducted. The results demonstrate that the independently developed indoor scaling model faithfully represents the actual spherical hinge’s stress condition, maintaining a margin of error below 15 % across all measurements. The data clearly show that axial stress on the outer slider exceeds that of the inner slider by 12.9 %–19.7 %, driving home the need for reinforced compression materials and a more strategic load distribution in the outer slider’s design. This disparity underscores why we cannot cut corners when optimizing the outer component. The proposed indoor spherical hinge model provides a robust methodological framework for evaluating the performance of swivel bridges under a variety of critical conditions, including wind loads, unbalanced moments, and uneven counterweights, thereby contributing to the advancement of bridge engineering and structural safety.