Numerical Analysis Of Bond Performance Of BFRP-concrete Interface Under Freeze-thaw Cycle-fatigue Coupling

In fiber reinforcement technology,FRP-concrete interface bonding behavior is always an important research point.However,although FRP material has been used for a long time,the current research results show that BFRP,as one of the younger FRP materials,has not been fully studied in the direction of interface bonding.Moreover,most of the existing research methods are directly used to explore the mechanism of interface bonding,and the emphasis on finite element numerical analysis is not enough.Combined with ABAQUS software and FE-SAFE software,the numerical analysis of the double-sided shear specimen with three variables of bond length,adhesive layer thickness and concrete strength under the coupling action of freeze-thaw cycle and fatigue load was carried out.The following work has been carried out in this paper:(1)Using ABAQUS order thermal stress coupling analysis module of concrete to50,100,150,200,four kinds of freezing and thawing cycles of finite element simulation,the temperature of concrete after freeze-thaw,stress,strain and damage contours of different freeze-thaw cycles,the simulation result of different strength grade of concrete block has carried on the contrast analysis,discusses the test results of the regression formula of freeze-thaw damage;(2)By using ABAQUS software,the BFRP under static load and concrete interface for finite element simulation,combining with the FE-safe software interface under constant amplitude fatigue load for the finite element simulation of the interface is obtained under static load and fatigue load bearing performance,through the analysis of different sub parameters such as thickness,bond length,concrete strength grade,the failure modes of the specimens,limit load,stress and strain distribution,the load-slip curve,summed up the effect of various parameters on the BFRP and concrete interface and the rules of the development of the fatigue damage;(3)The freeze-thaw fatigue coupling model based on heat conduction simulation and the freeze-thaw fatigue coupling model based on freeze-thaw damage formula were calculated respectively,and the results were compared.The ultimate load,stress and strain distribution,load slip curve and fatigue life of the models with different freeze-thaw cycles were compared after the coupling action of freeze-thaw cycles and fatigue load.The influence of the number of freeze-thaw cycles on the interface performance was analyzed,and the failure rule of the coupling action of freeze-thaw cycles and fatigue load on the interface performance of the specimens was summarized.