Design And Research For Displacement Limiter Of Anti-stretch Anode System

The first domestic anti-stretch anode system is expected to be installed on a jacket platform in the South China Sea.The design advantages of this system are simple and flexible installation and easy inspection and repair,the disadvantage is that the system is vulnerable to external environmental factors and destroys the failure,specifically,under the influence of environmental loads such as wind and wave currents,the composite cable in the system will be deformed to generate a lateral displacement,excessive lateral displacement will cause the composite cable to collide with the platform,which is a fatal hazard to both the composite cable structure itself and the jacket platform.Therefore,how to reduce or avoid the excessive lateral displacement of the composite cable is a major technical problem that determines whether the anti-stretch anode system can be successfully applied to engineering.It is not difficult to imagine that there are two measures that can be used to avoid the collision of the composite cable,one is to increase the tension of the composite cable and increase its geometric rigidity,the second is to install a displacement limiter at the appropriate position of the jacket and to avoid collision by the mechanical limit method.occur.Through calculation and analysis,it can be seen that the combination of the above two measures is economical and reliable,and the displacement limiter can refer to the bellmouth structure used for marine riser bending measures.The article first uses OrcaFlex software to prove the necessity of installing a displacement limiter,and gives the general design flow of the bellmouth-type displacement limiter,and gives a method to determine the minimum tip tension of the composite cable.Then,five different linear bellmouths were compared and analyzed,and it was concluded that in all types the bellmouth with the curvature was linearly related to the arc length is the best one overall performance.The above-mentioned linear bell mouth is applied to the displacement limiter,and ANSYS software is used to check the strength of the device.Finally,the interference analysis was performed on the composite cables of two sets of anti-stretch anode systems installed,and the calculation results meet the engineering practice requirements.