The effect of FRP stiffness variation on FRP debonding from concrete

In wet lay-upfiberreinforced polymer (FRP)bonded concrete members,fibersheets are appliedbyhand and the cured FRPs do not have constant properties.Therefore, the behaviour of FRPbonded concrete specimens varies among specimenseventhesame materials are used.In thisresearch, a mathematical method is used to predict the variationofload versus deflectionresponses of FRP bonded concrete specimens subjected toMode I andMode II loading due tothe variation of FRP properties.In an effort to effectively model the variation ofFRPproperties,a randomwhitenoise using a one-dimensional standard Brownian motion is added to thegoverning equationsofFRP debonding from concrete subjected toMode I andMode II loading,yielding a stochastic differential equation.The bounds of load vs. deflection responses with 95%probability are found for different experimental tests. The variationsofFRP stiffness for thesetests are also determined by a systematic method.