Investigation on Shear Strength of Steel-Polymer Adhesive Interface in Plastic Pipe Reinforced by Cross Helically Wound Steel Wires

摘要

Shear strength of fibre-matrix adhesive interface is crucial important to the mechanical performance of fibre-reinforced plastic pipes and fittings, due to its function for load transfer between the fibre and the matrix. In this study, pull-out tests of steel-polymer specimens were carried out with different embedded lengths. Ultrasonic scanning was adopted to monitor the failure procedure of the interface. From the analysis of UT scanning graphs, it could be determined that the studied steel-polymer interface failed rapidly on the whole embedded length under the maximal pull-out force, but not in the manner that crack initiated from a stress concentration point under a relatively small pull-out force and then propagated gradually. Different kinds of pull-out analytical models were discussed. Finally the analytical model of yielding interface was applied to characterize the steel-polymer interfacial adhesive property. Combing with experimental results of pull-out tests of different embedded lengths, the nominal bond shear strength was calculated out.