Mechanical model of bolted flange connection structures with thin flanges considering non-coordinated deformations of sectors

This study addresses the bolted flange connection structures with thin flanges by proposing a novel stiffness model that considers the non-coordinated deformation characteristics between adjacent sectors under load. Initially, the entire structure is divided into several sectors based on the number of bolts, and spring elements are employed to simulate the deformation characteristics both within the sectors and between them. Subsequently, theoretical expressions for the stiffness of each equivalent spring element are derived from the relationship between partial structural forces and deformations. Finally, the accuracy of the stiffness model is validated through numerical simulations and tensile experiments. The results indicate that the error in the non-coordinated deformation quantities between theoretical calculations and simulation, as well as experimental results, remains within 5%. The stiffness model established in this paper is capable of accurately predicting the non-coordinated deformation characteristics between sectors of thin-walled bolted flange connection structures under both normal and bolt loosening failure conditions.