Research On Folding System Of Ship Transport Cable-bridge

At present,the research on the barge overturning device at sea has practical application significance.This paper proposes a folding cable bridge scheme for cargo transportation of naval ship personnel and takes it as the research object.The cable bridge has the characteristics of flexibility,large expansion ratio,compensation for irregular relative motion caused by wind and waves among ships,and it can also realize continuous barge of long-distance personnel and cargo.Based on the typical motion parameters produced by ship under the disturbance of sea waves,the technical index of compensating ability of cable-bridge scheme for multidimensional composite motion of ship is formulated,and the design index of cable-bridge scheme is given.Then,according to the requirements,three configuration schemes of cabletower,receiving frame and corresponding folding bridge body are designed.Then,the advantages and disadvantages of three configuration schemes of cable-tower,receiving frame and folding bridge body unit are compared.Finally,the optimal folding bridge body scheme is selected.Configuration analysis of the folding mechanism of bridge unit is carried out by using the method of synthesis of parallel mechanism with few degrees of freedom in space.This method can synthesize the abstract screw mechanism,grasp the essence of the mechanism,and construct a variety of mechanisms that meet the requirements on the premise of ensuring the realization of the movement law of the mechanism.Then,the deformable bridge guardrail mechanism is analyzed in detail with the screw theory.The degrees of freedom of the guardrail mechanism under different configurations are solved and verified.The motion forms of the guardrail mechanism under different configurations are analyzed.Two equivalent mechanisms of bridge element,2-RPP/RPR mechanism and 3-RPR mechanism,which can realize two-shift and one-turn motion,are analyzed.The mechanism principle of 3-RPR mechanism is analyzed by screw theory,and its degree of freedom is calculated.Then,the mapping relations of position,velocity and acceleration of 3-RPR mechanism are analyzed in detail,and numerical examples are given.The horizontal tension of suspension cables in fully deployed state is calculated simply,and the types of load-bearing cables are compared and selected accordingly.Then the tension and vector of suspension cables in empty state and completed state are calculated respectively.Finally,the stress and deflection of the selected bridge frame are calculated and analyzed by using finite element simulation software ANSYS Workbench modeling.