Experimental Study And Analysis On The TLP Tendon Connectors

Tension-Leg Platform(TLP)is one of the major floating structures for oil and gas development in deep-sea area.The platform has been a huge concern in the international community due to its good dynamic characteristics and stability.It is the very first time to use the platform for the applications and development of oil and gas in China.This thesis designs a Tendon Connector who is suitable for 500-meter water depth as well as a 40-inch tendon diameter TLP,and analyzes the main components of a Tendon Connector theoretically and experimentally.This thesis introduces the development and research status of existing tendon connectors in the first place.Then proposes a structure scheme of the top and bottom connectors of the tendon,according to the actual working conditions and design requirements of TLP.On this basis,the driving method,sealing method,hydraulic system,clamping mechanism,guide components and bearing components of tendon connector is analyzed and designed.Besides,a tendon installation procedure is established depending on the working principle of the tendon connector.This thesis analysis the carrying capacity before and after clamping for the top connector holding clip slip.And a Distribution model of load distribution along the position is obtained based on the elastic deformation model and the deformation synergistic condition of Latch.The optimal teeth number is proposed by analyzing three kinds of Latch with different teeth number.The best bearing capacity of the teeth is studied and verified by finite element software according to the internal stress model of variable cross-section cantilever.Finally,the contact stress concentration of the tooth is optimized,and the optimal pitch,tooth height and tooth angle parameters are obtained.For the flexjoint in the tendon connector,one 1 in 4 reduction ratio model was established as well as a Mooney-Rivlin rubber constitutive equation was fitted.In the thesis,the compressive stiffness equation of flexjoint is established based on the compressive stiffness model of cylindrical laminated rubber of Lindley and Gent.And the same method is used to establish the equation of rotational stiffness.The effects of rubber material Poisson's ratio and thickness distribution of flexjoint on the stiffness of flexjoint were analyzed.Under compression,rotation and compounding conditions,the stress and strain distributions of metal and rubber were studied.The results were compared with the limits of metal rubber to verify the strength of the flexjoint.An experimental platform is set up to verify the performance of flexjoint.The factors affecting the stiffness as well as the bearing capacity and mechanical properties of the flexjoint are analyzed and verified,by operating compression and rotational stiffness test of three kinds of flexjoint specimens.A bottom connector mockup of the tendon is made.Then land and pool installation experiments are operated to verify the correctness and rationality of its internal guidance program.At the same time,it can prove the secondary locking mechanism can play the role of tendon anti-prolapse and provide valuable reference for follow-up researches.