Study On Underwater CFRP Repair Performance Of Steel Offshore Platform

With the development of marine engineering and the exploration and development of marine oil and gas resources,research on offshore platform technology has become a hot spot in the marine engineering community and a large number of deep-sea offshore platforms have been built around the world.Platform corrosion caused by marine platform service and the inevitable collision damage in the process of production operation is a significant problem.The relevant standards for underwater repair of steel structure have not been updated to incorporate recent developments,so research on marine platform repair technology has become an important topic at present.In this paper,through the study of underwater adhesive systems,an underwater composite epoxy adhesive for underwater construction is examined,and static strength tests of CFRP bonded steel plate are made using this adhesive.The influence factors of the reinforcement and repair of steel structures by CFRP are analyzed.The main contents of this paper are divided into the following parts:First,this paper introduces the related theories of underwater epoxy resin bonding,including the principle of underwater bonding,the failure mechanics and failure forms of the bonding joint,the factors that affect the strength of the adhesive and so on.The composition of the epoxy resin adhesive and the role of each component are introduced,and modification methods and the toughening mechanism of Nano SiO₂ modified epoxy resin are introduced.Secondly,underwater epoxy matrix adhesives are tested for underwater vertical flow performance,and the feasibility of underwater construction is determined.The Nano SiO₂ modified underwater composite epoxy adhesive was prepared.The mechanical properties of the adhesive were tested according to the relevant national standard.The test contents included shear strength,tensile strength,compression strength and so on.An orthogonal experiment was designed and the effects of three factors on the mechanical strength of adhesive were studied,including Nano Si O₂,adhesion promoter and wetting leveling agent.The influence of dispersion and dosage of Nano SiO₂ on the mechanical properties of underwater epoxy composite adhesive was investigated.Finally,a loading experiment of steel fiber reinforced polymer underwater reinforcing and repairing steel components was carried out using the best performing underwater adhesive.The peeling failure characteristics of CFRP cloth and its effect on yield load and ultimate load are analyzed.The influence of the bonding length,the width of bond,the number of CFRP layers and the anchorage method on the reinforcement effect is investigated,and the bond performance of the steel plate and the CFRP cloth is systematically studied.It is proved by the experiment that the Nano SiO₂ modified underwater composite epoxy adhesive has excellent curing performance and good mechanical properties,and it has achieved the desired experimental purpose.In this study,some rules and conclusions have been obtained through the experimental study of CFRP repair and reinforcement of steel plate,which has certain reference value for underwater structure reinforcement and restoration engineering.