Research On The Dynamic Response Of Foam Filled Fender Maritime Barrier System With Small Waterplane Area

The maritime barrier system can physically separate dangerous vehicles from the safe areas of sensitive zone such as naval ports,nuclear power plants,offshore platforms,bridges and petrochemical wharf.It can resist impact loads and complex sea conditions through a flexible energy dissipation method with large displacement.Based on the hydrodynamic solver ANSYS AQWA and the nonlinear dynamics solver ANSYS/LS-DYNA,numerical study was carried out on the hydrodynamic performance and impact resistance of a new foam filled fender maritime barrier system with small waterplane area in this paper.In terms of hydrodynamic performance research,based on the second-order Stokes wave theory,the time-domain and frequency-domain response characteristic of the maritime barrier system under the action of regular waves are analyzed at first.Then the influence of the draft of the foam fender and the environmental water depth on the dynamic response of the floating body and cable tension is investigated.Further,based on the spectral analysis method,the influence of the rope stiffness and wave incidence direction on the frequency domain response amplitude operaters(RAO)of the maritime barrier system under the action of irregular waves is explored,and the time domain response of maritime barrier system under different sea conditions with considering wind and current load is statistically analyzed.The numerical simulation results provide references for the counterweight of the anchor rock on the seabed and the reservation of the safe buffer area;the parametric analysis of the environmental water depth,the draft of the foam fender and the rope stiffness provides the basis for the subsequent optimization of the maritime barrier system;the study of system RAO under different wave directions revealed the most dangerous situation.In the aspect of impact resistance study,the influence of fully coupled model and semicoupled model on calculation accuracy and efficiency is compared at first;further,the effect of the vessel mass,velocity impact position and foam fender material density on the collision force,cable tension and energy dissipation were explored based on the semi-coupled model,and the velocity and displacement response of the small vessel and the foam fender during the collision are analyzed.Finally,a preliminary evaluation of the impact resistance of a new type of foam fender maritime barrier system with spines was carried out.The design of the rope strength of the maritime barrier system meets the engineering requirements;it can quickly reduce the velocity of the vessel;the spines on foam fender can cause damage to dangerous vessel;the research of the foam density on collision response provides a basis for subsequent optimization.