ABSTRACT
HydroQus is a plug-in based on potential flow theory that generates interactive hydrodynamic forces for the commercial FEA code Abaqus/Explicit. HydroQus requires hydrostatic and hydrodynamic constants obtained through frequency response analyses. These constants are hydrostatic restoring stiffness, added mass, wave damping coefficient, and 1st/2nd order wave excitation forces corresponding to 6-DOF motions. As soon as a FEA is executed, HydroQus receives displacements, velocities, and accelerations at the COM from Abaqus/Explicit at every time increment and returns updated hydrostatic force, radiation force, and wave excitation force to Abaqus/Explicit at next time increment. This paper suggests two sample problems of ship-to-iceberg collision and level ice breaking. When an icebreaker collided with an iceberg, effects of hydrostatic and hydrodynamic forces were analyzed in terms of post-collision motions. Those forces significantly affect ship motions after collisions. A model ship of the icebreaker advances level ice. Level ice was modeled as hexahedral or tetrahedral continuum solid elements. By applying the continuum damage mechanics to the Drucker-Prager yield function, global splitting failure and local bending failure of flat ice can be naturally generated. Predicted mean ice resistance was successfully agreed with towing test results.
