Investigation On Adhesion Of Unbonded Flexible Pipe End Fitting

End fitting is a major equipment of connecting pipelines and floating, and the connect performance of tension armor wire and end fitting is directly determines the result of loading capacity. The essence of study on connect behavior of the fold wire with epoxy resin is the study of adhesion properties between fold wire and epoxy resin.Paper first simple introduce the structure of un-bonded flexible pipe and the end futing, and it formulates a method of investigation on end fitting adhesion based on the adequate research and analysis of the development of adhesion mechanism, adhesion mechanical and the adhesion of end fitting. This method includes fitting the material property of adhesive layer, FEA of adhesion and verifying feasibility of numerical model through pull-out test and fold pull-out test. This paper find:shear ultimate strength is the largest parameter influencing adhesion properties through analyzing the model of single-lap shear adhesive layer parameters, the overlap length has a more great effect than thickness of epoxy through analyzing the pull-out model with thick epoxy. According to folding bent pulled-out numerical model and the experiment results for compared, the failure process of end fitting can be divided into four stages:wire yield, adhesive failure between steel and epoxy, steel wire break. The strength of straight steel and material property of epoxy and steel is more effective than fold corner. And the fold comer and strength of first fold part have influence to the fatigue property of end fitting.Research of this paper is sponsored by Hi-Tech Research and Development Program of China (863 Program,2012AA090314).