Experimental Study on Propagation Rule of Semi-elliptical Surface Crack in Steel Plate Strengthened with FRP under Cyclic Bending Load

摘要

Strengthening steel structures containing semi-elliptical surface crack with fiber reinforced polymer (FRP) can delay crack propagation,and increase the service life of structures.In this paper,carbon fiber laminate (CFL),which has independent intellectual property,was adopted to strengthen X80 steel plate containing a 3D semi-elliptical surface crack,and based on this study object,the surface crack propagation rule in the specimens was studied by experimental method under cyclic bending loads.The results show that 3D semi-elliptical surface crack propagation rates in the crack length direction and crack depth direction can be described by corresponding Paris equation for the specimens strengthened with CFL,the constant coefficients in Paris equation can be obtained by fitting the data from fatigue crack propagation experiments,and stress intensity factor of the surface crack in steel plate strengthened with CFL can be obtained by numerical calculation with FEM.