Dynamic response and local buckling behavior of offshore tubular T-joints under drop-weight impact loading
Abstract
The structural integrity of offshore oil and gas platforms is critical for risk management in harsh marine environments. Welded tubular T-joints, extensively used in these structures, are vulnerable to low-velocity impact loads from vessel collisions or dropped objects. This study experimentally investigates the dynamic response and impact resistance of largescale tubular T-joints under drop-weight impact. Two Q345 seamless steel T-joint specimens were subjected to impact energies of 11.3 kJ and 14.5 kJ. An integrated data acquisition system was employed to record dynamic strain, impact force, and displacement. The results reveal that the failure mode is dominated by local buckling at the chord intersection, forming distinct elliptical plastic hinges. Energy dissipation analysis demonstrates that approximately 90% of the impact kinetic energy is absorbed through the coupling of local plastic deformation and global bending of the chord. Furthermore, the dynamic ultimate bearing capacity of the specimens is significantly enhanced by 1.61 to 1.97 times compared to their static capacity , primarily governed by the material strain-rate effect. This study identifies critical areas for future data acquisition improvements and provides essential empirical data that can be integrated into smart safety perception systems for offshore facilities and oilfield stations.