Abstract:In order to study the interlaminar mechanical behavior of regenerated composite pipes with thin-walled lining, tangential and normal tensile failure tests are carried out on the composite pipes with corroded defects and thin-walled stainless steel lining. Based on the test results, a finite element analysis model is established for the repaired pipes with corroded defects. The test results of test specimen under the effect of tangential force show that with the increase of pipe steel corrosion extent with corrosion defects, bonding layer and the base pipe steel strip gradually decreases, the ultimate strength of the interface between the layers increase gradually, and with the increase of the corrosion loss rates, the interface cohesive force has a slight increase. But with the increase of proportion of binding material failure, this increased trend gradually flatten out. The tangential failure of interlayer interface is mainly due to the failure of cohesive force of binder. The test results under normal force show that the failure modes of each specimen are basically the same, and the failure is mainly the failure of cohesive force of the bonding layer. A bilinear constitutive model of tangential stress and relative displacement at interlayer interface of composite pipes is established by difference method. The relation between normal stress and relative displacement at interlayer interface can also be simplified to bilinear constitutive relation. The finite element analysis model is used to analyze the specimen, and the analysis results are in good agreement with the test results. The bilinear interfacial cohesive force model can accurately simulate the interlaminar mechanical properties of thin-walled composite pipes in the finite element model analysis. The research content and results can provide a theoretical basis for the trenchless continuous lining repair technology of buried pipeline.