Parametric Study of Combined Mechanisms in Energy-Absorbing Tube for Rail Coupler

Mitigating impact energy in rail vehicle collisions through energy-absorbing components is paramount for passenger safety. This study investigates an innovative energy dissipation system incorporating combined shrinking and splitting deformation mechanisms subjected to axial impact loading. Nonlinear implicit dynamic analyses employing LS-DYNA are conducted to elucidate the deformation characteristics and energy absorption (EA) capacity. The finite element model and boundary conditions are established in accordance with the EN15227 standard for rail vehicle crashworthiness. The results demonstrate a substantial enhancement in EA capability facilitated by the coupled mechanisms, attributable to frictional energy dissipation during the shrinking phase and the induction of a secondary force peak in the splitting phase. A parametric study is subsequently undertaken to evaluate the influence of geometric parameters, including bushing angle, splitter radius, tube thickness, and bushing-splitter clearance, on specific energy absorption. Tube thickness emerges as the most significant parameter, yielding a 64% increase in EA.