Torsional Fatigue Characteristic Research And Test Device Design Of Subsea Connectors

The subsea collet connectors torsional fatigue test is the ministry of industry and information technology major "The subsea collet connectors and its supporting machinery testing technology with the equipment research" sub-project " The subsea collet connectors torsional fatigue test system research".Development of marine engineering equipment system in our country is still at the starting stage,although progress has achieved some results in the subsea connectors technology research and development,but the development test method in subsea connectors and test device or invacant state technology.The main purpose of the research is to develop subsea connectors torsion fatigue testing device,the device can simulate working condition to finish fatigue test of the connectors.This paper takes the undersea connectors by the torsion fatigue characteristic as the research basis,in order to torsional fatigue testing device as the research object,the paper studies on the movement ofloads,device of mechanical structure and hydraulic structure.In actual operating conditions,the pipeline will be impact by connected across the load,the load including wave,flow and crustal movement of the earth,of which the most important is the impact load caused by waves and currents.When the waves and currents in the jumper pipe will impact loading,because of the subsea collet connectors has played pivotal role connected subsea wellhead and cross connection pipelines,so the role in bridging the pipeline impact load will form the torsional moment of the subsea connectors.To research the actual sea state,At the same time,combined with the mechanical vibration,fluid mechanics and ocean engineering related theoretical knowledge of jumper pipe load analysis,finally it is concluded that subsea connectors by torque and frequency.Through the analysis of the change of subsea connectors,we identify the key requirements for technical device for testing fatigue torsional subsea connectors and the design index.Based on subsea connectors torsional fatigue test device to determine the basic requirements,combined with practical application conditions to complete the usubsea connectors torsion fatigue testing device of the mechanical structure system,the overall design scheme of the hydraulic system and control system.On the basis of the mechanical structure system overall scheme design,the mechanical structure of the test device is designed in detail.Three-dimensional modeling of the mechanical structure by using UG NX8.0 software,and the use of finite element analysis software for the modal analysis of the key parts of the system structure.The six order natural frequency of mechanical components derived from modal analysis are compared and verified with the torsional frequency,in order to determine the safety and rationality of mechanical structure.According to the overall scheme of subsea connectors torsion fatigue testing device,research and design of the hydraulic servo system of the device,at the same time,according to the actual demand to develop a working principle diagram of hydraulic servo syste.Accurate calculation and reasonable selection of parameters of the hydraulic servo system components.The hydraulic system model is created and simulation using the simulation software AMESim,according to the set command signals corresponding to the actual requirements,simulation of subsea connectors according to the frequency of thetorsional fatigue testing,draw the test curve and the analysis,and then verify theaccuracy of the device for hydraulic system.