Coupled hydrodynamic-structural analysis on reuseable launch vehicle landing on barge

Sea-based landings offer a safer alternative to land, reducing risks to property and life while enabling the recovery of reusable launch systems to reduce launch costs.However, the dynamics of such landings pose significant challenges, particularly in minimizing structural damage and ensuring efficient recovery.This study examines the coupled hydrodynamic-structural response of a launch vehicle on a barge during touchdown, focusing on the coupled dynamics of the two systems.A time-domain model of the barge is developed using the Cummins equation, incorporating hydrodynamic parameters added mass and damping determined using HAMS.The launch vehicle is modelled as an equivalent beam and coupled to the barge, enabling the simulation of key transient behaviour during offshore landing events while allowing parametric studies and rapid design iterations.The sensitivity of the transient response of the coupled model is analysed with variability in the touchdown velocity and landing location.The simulation framework developed captured key hydrodynamic-structural excitations of the system.Results indicate that offset landing induces coupling between heave and pitch modes, while structurally exciting the bending modes.However due to maintain-ing of sufficient bandgap between the hydrodynamic and structural modes the coupling effect is reduced and response is of low magnitude.