An experimental and numerical study on the behaviour of tubular components and T-joints subjected to transverse impact loading

This paper presents a series of experimental and numerical studies on the behaviour of scaled tubular components and T-joints subjected to transverse impact loads. These scaled specimens are made to represent tubular joints on a jack-up or jacket offshore platform. They are struck transversely by a falling wedge indenter. Measurements are taken of the impact force, the permanent deformation and the displacement of the falling wedge. The force-displacement responses show distinctly three stages, which are the initial vibratory stage, the steady deflection stage and the rebounding stages. The tests demonstrate that the brace increases the energy absorption of the chord members, and that the T-joints carries more impact loads when subject to impacts of higher impact velocities. Numerical simulations are also carried out for these scaled tests while the steel is modelled based on the measured strain-stress curves. Good agreements between tests and simulation were achieved. These numerical simulations provide additional information about the structural behaviours. It is also demonstrated that properly modelling the support structures in the lab tests is also important for accurately capturing the structural behaviours.