IDENTIFICATION OF BOND-SLIP RELATIONSHIP FOR EB-FRP INTERFACE FROM LOAD-SLIP CURVE

摘要

Bond-slip relationship of externally-bonded (EB) fiber reinforced polymer (FRP) joints can be identified from pull-off tests by either direct measurement or indirect analytical identification from load-slip response curve. Indirect analytical method is gaining popularity in recent literature due to its advantages in producing more consistent and accurate result. Currently, loaded end slip vs applied load curve is used for identification of bond-slip relationship, and free-end slip has been ignored. This work shows that ignoring free end slip can result in significant error in bond-slip relationship. Analytical method is used in this work to derive closed form solutions for FRP strain, interface slip, and also for relating slips to bond strength of EB-FRP joints. The analytical solutions are valjdated by experimental results. Using the analytical solution, it is clearly shown in the paper that free end slip will affect results, and hence, should be considered in deriving bond-slip relationship of EB-FRP joints, especially when bond length is short.