Analysis Of The Static Bearing Capacity Of The CFRP-reinforced Jacket Platform Members Under Axial Compression

With the continuous development of the oil and gas industry,the marine jacket platform has become an important support for offshore oil and gas development and exploitation.As far as Shengli Oilfield is concerned,more than half of the in-service jacket platforms have damages such as depressions,cracks and large-area corrosion,which seriously affect the structural safety and service life of the platform.Compared with the traditional steel structure repair and reinforcement technology,carbon fiber composite material(CFRP)reinforcement technology has the unique advantages of no increase in weight,convenient construction,low cost and high efficiency,which makes it popular in the reinforcement of engineering structures.In order to evaluate the reinforcement effect of carbon fiber reinforced composites used to reinforce the repaired jacket platform circular steel tubular members under axial compression,carbon fiber reinforced composites were used to strengthen the jacketed steel tubular specimens without corrosion defects and corrosion defects.Research on static bearing capacity.The CFRP reinforcement and unreinforced axial compression static test were carried out on the scale test piece of the circular steel pipe of the jacket platform.There are three sets of five test pieces,and the test pieces are divided into two types:round steel pipe short column and round steel pipe long column.The two round steel pipe short column test pieces all contain corrosion defects,and the three round steel pipe long column test pieces have two corrosion defects and one contains no corrosion defects.The test pieces were set up with a control group to evaluate the effect of CFRP reinforcement.From the test results,the bearing capacity of CFRP-reinforced specimens is increased by about 40%compared with that of unreinforced specimens,and the presence of CFRP effectively limits the deformation of steel pipes,which not only limits the strength damage of steel pipes,but also It can limit the instability and damage of steel pipes.Through the steel material test and the constitutive relationship model of carbon fiber composites,the finite element analysis model was used to analyze the five round steel tube specimens involved in the test by using ABAQUS finite element analysis software.The accuracy.On this basis,the diameter of the wall thickness ratio,the number of reinforcement layers and the direction,the length ratio of the reinforcement,the depth of corrosion and the angle are taken as parameters to test the CFRP reinforcement of the circular steel pipe short column without corrosion defects and the short steel column with corrosion defects.The parameters were analyzed.A series of parameters were also analyzed for CFRP-reinforced round steel tube long columns without corrosion defects and round steel tube long columns with corrosion defects.Through the analysis of experimental phenomena and finite element model,the equivalent section method,combined with the concept of CFRP and steel tube modulus ratio,is used to derive the static bearing capacity formula of CFRP-reinforced short steel columns without corrosion defects under axial compression.The formula results are compared with the finite element and the test,and the error does not exceed 5%,which verifies the usability of the bearing capacity formula.At the same time,with reference to China's "Steel Structure Design Code",combined with the equivalent section method,the formula for calculating the stability bearing capacity of CFRP-reinforced steel tubular long columns without corrosion defects is derived.The calculation results of the bearing capacity formula are compared with the experimental and finite element results.In contrast,the availability of the stability bearing capacity formula was verified.