Dynamic Analysis And Simulation For Crane Ship Of Transporting And Lifting Girders

Crane of transporting and lifting girders plays an important role in constructing the bridge and offshore platforms. The crane ship's dynamic response is very complex, the impact factors include external wave force, fluid viscous drag force, cable power, wind force and interactive coupling of waves, hull, and suspend payload system. Therefore, the dynamic analyses of the crane, particularly analysis coupling characteristics, have great significance to crane's design and secure operation.Here focus on crane ship of transporting and lifting girders, mainly including the following aspects:Firstly, the nonlinear dynamic response of suspend payload system was analyzed during the operation. The four-point suspension system was simplified as a double pendulum model based on geometric constraints. The dynamic equations of the suspend payload system were established using Lagrange equations, and its dynamic response was simulated under regular wave conditions.Secondly, time delayed feedback control was introduced, using the method of change the rope length, to control the swing of suspend payload system. The control effect was analyzed under the different length of the rope.Finally, the crane ship's virtual prototype model was established and analyzed. The external loads to the hull were simplified as equations, to simulate the works of crane ship with a more realistic external environment. At the same time, the role of lifting ropes used Bushing joint to simulate. The crane ship's dynamic response and coupling were analyzed under virtual prototyping environment.The results show that: the suspend payload system of such crane ships can adopt linear swing analysis under certain conditions. It's effective that using the time delayed feedback method to control the swing, based on changing the rope length. The waves, hull, and suspend payload system have interaction coupling with each other. A rational role period of hull can reduce the couplings effect. This study provides the reference to crane ship's production design, swing control and engineering operations.