SIMULATION ANALYSIS OF LOAD DISTRIBUTION OF GFRP BARS IN CONCRETE UNDER DIRECT PULLOUT

摘要

The objective of this study is to investigate the bond strength and load distribution of glass fiber reinforced plastic (GFRP) bars in concrete under direct pullout. The pullout tests of two GFRP bars with two diameters of 12mm and 14mm embedded in concrete specimens were carried out. The nonlinear finite-element model for bond behavior was established and the simulations including load-slip curve, GFRP stress distribution, bond stress distribution and local slip distribution along the embedment length were analyzed. The studies indicate that the load-slip curve is divided by five stages from the specimen loaded initially to failure. GFRP stress distribution along the embedment length is nonlinear. With increasing load, the peak bond stress improves and tends to move progressively towards the free end. Local slip distribution is typically exponential or quadratic curve. Additionally, the simulations results on bond strength, slip and loadloaded and free end slip relationship curve, GFRP stress distribution agreesclosely with the experimental results.