Sloping structures are widely used in ice-infested waters because of their ability to reduce ice loading, by inducing a bending failure in ice sheets. From model test data, a significant velocity effect on the breaking load of ice sheets has been reported. In this paper, the ice-fluid interaction process is investigated by adopting the Euler-Bernoulli beam theory for ice sheet, and the potential theory for the underlying fluid domain. Accounting for the inertia effect of ice sheet and the hydrodynamics of sea water beneath the ice sheet, the results demonstrate a velocity effect on the ice breaking loads in plane deformation, which compare well with available model test data. Moreover, our model formulation and implementation is such that the solutions for different ice velocities can be obtained rapidly from the reference solution, which facilitates the development of a real-time simulator. It is also shown that the velocity effect depends on the ice compressive strength and the angle of sloping structure.