Resonance of the roll motion of a two dimensional barge induced by triple frequency wave force

The resonant behaviour of the roll motion of a two dimensional (2D) barge in nonlinear regular beam waves of low frequency has been investigated through the velocity potential theory. The higher order boundary element method (BEM) is adopted to solve the boundary value problem. The mixed Eulerian-Lagrangian (MEL) technique and the 4th-order Runge-Kutta time stepping scheme are used to simulate the interaction of waves and the floating barge. The auxiliary functions are introduced to calculate wave loads and the coupled motion. Numerical results of a floating barge in regular beam waves are presented after convergence study and verification. The resonant behaviour of roll motion excited by the third order harmonic force at the triple wave frequency has been investigated.