【摘要】 本文对工业化制备的钢-连续纤维复合筋(SFCB)制品进行了单向拉伸和反复拉伸试验,观察其破坏过程和破坏特征,测定其初期刚度、二次刚度、屈服强度、极限强度、卸载刚度、残余变形。试验结果表明,SFCB的荷载-应变关系曲线在纤维断裂前呈现出明显的双折线,钢筋屈服后SFCB具有稳定的二次刚度、小的残余变形和良好的可恢复性能。根据材料的复合法则推导出了SFCB单调加载下应力-应变关系的理论计算模型,针对根据现有钢筋和纤维材料恢复力模型直接采用复合法则得到的SFCB反复拉伸的理论模型和试验结果误差较大的情况,基于SFCB反复拉伸的荷载-应变试验曲线特征,经过统计分析,构建了SFCB反复拉伸下应力-应变关系恢复力模型,该模型良好地揭示了SFCB在反复加载下其卸载模量随塑性发展而逐渐退化的规律,与试验数据进行比较,发现均吻合较好,证明了可以通过理论计算对SFCB的力学性能进行预测和设计。更多还原

【Abstract】 Uniaxial and cyclic tensile tests of steel-FRB (fiber reinforced polymer) composite bar (SFCB) products were conducted,with the destruction and damage characteristics observed and the initial stiffness,post-yielding stiffness,yield strength,ultimate strength,unloading stiffness,and residual strain of the specimens measured. Test results showed that the load-strain curve of SFCB was bilinear before fiber fracture and exhibited stable post-yielding stiffness,small residual strain and good recoverability after the reinforcement yielded. Since the theoretical model for the stress-strain curve of SFCB under uniaxial load derived from the mixing rule involves large error for cyclic test data,a Restoring Force Model for the stress-strain curve of SFCB under cyclic load was constructed by statistical analysis of the characteristics of the stress-strain test curve under cyclic tension. The Restoring Force Model could thoroughly display the pattern of the unloading modulus of SFCB degradation under cyclic tensile and the predicted results were in good agreement with experimental data,which proved that the performance of SFCB could be predicted and designed by the proposed model.更多还原