Numerical Analysis of KI of Semi-elliptical Surface Crack in X80 Steel Plate Strengthened with FRP under Tensile Load

摘要

Semi-elliptic surface crack is the common defect in metal structures. To ensure the structural integrity and security, the new material such as fiber reinforced polymer (FRP) was adopted for strengthening and repairing. In this paper, three dimensional semi-elliptic surface crack in X80 steel tension specimen strengthened with carbon fiber laminate (CFL) was studied, and numerical analysis was undertaken by Abaqus finite element software to study the stress intensity factor (SIF, KI) of the surface crack for CFL reinforcement effect. The results shown that, strengthening by CFL reduced the stress intensity factors of semi-elliptical surface crack significantly; Crack shape ratio a/c and crack relative depth a/B had a great effect on stress intensity factors of strengthened specimen; An expression for calculating stress intensity factors of semi-elliptic surface crack under strengthening condition was obtained by adopting MATLAB software.