Research On Longitudinal Motion And Load Of Cutter Suction Dredger Under Multi-point Constraints

The stress of spud is one of the main obstacles against jumbo cutter suction dredger development.Flexible spud is a solution to this problem.This positioning method allows a small longitudinal angle between spud and hull,thus relieve the bend and stress od spud to some extent.A specific jumbo cutter suction dredger and the cylinder-formed buffer system employed will be studied in this paper in theoretical derivation,numerical simulation and model test method.The theoretical calculation model will be established firstly.The motion and force of the CSD in multiple constraints will be analyzed and separated into a coupled problem of the hull,the spud and the buffer system.Establish the model for each part base on their own character and derivate the calculation formula related.Put them into a completed calculation model based on their connections and interactions.The final theoretical model is thus made.The numerical simulation method will be established then.With MATLAB software,the theoretical model will be transformed into a calculation procedure of this problem.The simulation results show that the buffer system has nearly no negative influence on the positioning capacity of ship,while its stress relieve capacity for spud is satisfying,especially in high sea state condition.The model test is carried out as well.The test model,scale ratio,procedure steps are designed and a spring buffer is made to simulate the buffer system.The test results also show the response character of ‘low efficiency in low sea state,high efficiency in high sea state’ of the buffer.In high sea state condition,the maximum moment at upper and lower clamp on the spud can be tremendously reduced.The buffer system has a good capacity of stress relieving and a small negative impact on the ship positioning.The overall trend of numerical simulation and model test is in accordance.