The collision between the vessels during skin-to-skin connected replenishment was modeled based on the multibody dynamics with unilateral contacts and classical marine hydrodynamics. With additional water mass taken into account the collision force expression was deduced for the vessels without anti-impact protection device, and relevant numerical simulation was presented. In order to improve the efficiency, during simulation process the identification of practical constraints for non-smooth system was converted into an extremum problem and solved with optimization theory. The preliminary simulation results were conformed to those of the relevant experiments as a whole, which proves that the new calculation method for the collision is available for the design of the anti-impact protection device.

An experimental system for an inverted pendulum with a location-limit was designed and developed. The mechanical model of the system was established. Through experiments and numerical analysis, the responses of the system in the cases of periodic and random excitations are discussed. Some complicated nonlinear dynamic behavior of the system is revealed. It is found that the noise has some impact on the system behavior. The conclusions will be useful for design and analysis of the structures with gaps.

Rattling vibration is one kind of harmful vibration during the gears drive transmission because of the piay with in the gear meshing. In this paper, a rattling system with stochastic damping was investigated. A discrete stochastic model described by mean map was established using nonGaussian technique, and using experimental conclusion to verify the reasonable conclusion.