Effects of thermal expansion coefficients discrepancy on the CFRP and steel bonding

Abstract

The long-term durability of steel structures strengthened by externally bonded carbon-fiber-reinforced polymer (CFRP) plates or sheets is a concern due to the discrepancy in the thermal expansion coefficients (CTE) between CFRP plate and steel. In the present study, the single-lap shear test was applied to study the variation of the bonding performances between CFRP plates and steel using different types of adhesive after 150, 300, and 500 temperature cycles from −20 °C to 40 °C. The result shows that the temperature cycle led to an insignificant reduction in the bond performance between the CFRP plate and steel. After 500 temperature cycles, the decrease in bond strength is less than 10%. Finally, the distribution of thermal shear stress under temperature cycles is simulated by the finite element method, which is consistent with the analytical solution in published literature.