Static Behavior of Tension Steel Plate Strengthened with Pre-Stressed CFRP Laminates

An experimental and analytical study was conducted to investigate the static performance of steel plates strengthened with pre-stressed CFRP (carbon fiber-reinforced polymer) in uni-axial tension. A linear elastic theoretical model was presented to predict the stress distribution of reinforced specimens. Static testing was performed on the double edge notched specimens strengthened by CFRP laminates at different pre-stressing levels. The theoretically predicted results were in good agreement with the experimental results. The results show that pre-stressed CFRP laminates had a large impact on the specimen's strength but resulted only in a moderate increase of its stiffness. An eccentricity due to pre-stressing was observed leading to bending effects which result in a non-uniform stress distribution. The test results indicated that the long-term pre-stress losses due to static and fatigue loading were slight because of the excellent mechanical properties of CFRP laminates. Therefore, the total pre-stress losses could be simplified as the short-term pre-stress losses with considering a safe factor.