摘要
为研究由玻璃纤维增强复合材料(GFRP)布、碳纤维增强复合材料(CFRP)箍筋、GFRP 纵筋与混凝土组成的新型组合墩柱,纤维增强复材(FRP)约束 FRP 筋增强混凝土(FCFRC)墩柱的抗震性能,基于OpenSees有限元软件开发FCFRC墩柱单调及往复水平荷载作用下的数值模拟模型,在此基础上以轴压比、剪跨比、纵筋配筋率、CFRP 箍筋和 GFRP 布约束水平、混凝土强度和截面尺寸为变量进行 5 184 个FCFRC墩柱的单调静力弹塑性分析(Pushover分析),获得上述影响变量对屈服承载力、峰值承载力、弹性刚度、弹塑性刚度以及极限位移角等建立三折线恢复力模型的关键参数的影响规律;结果表明:提高轴压比、纵筋配筋率、混凝土强度和截面尺寸均能提高屈服承载力和极限承载力,箍筋和FRP 布约束水平的影响相对较小.基于参数分析结果,获得了恢复力模型骨架曲线关键参数的计算式;此外还提出了FCFRC水平力-位移加卸载滞回规则,结合骨架曲线和滞回规则提出了FCFRC水平力-位移恢复力模型,通过与试验结果比较验证了恢复力模型的适用性.
Abstract
To study the seismic performances of a novel of GFRP-confined FRP bar-reinforced concrete piers,also called FCFRC piers which were constructed of GFRP rebars,CFRP stirrups,GFRP sheets,and concrete,a numerical simulation model for FCFRC piers under the monotonic and cyclic horizontal loads was developed based on software OpenSee.By the model,taking axial compressive ratios,shear-span ratios,lon-gitudinal reinforcement ratios,confining levels of CFRP stirrups and external wrapped sheets,strength de-grees of concrete and sizes of cross sections of piers as variables,pushover analysis was conducted on 5 184 FCFRC pier specimens.The effect of the above variables on key parameters of the trilinear resilience model with the yield bearing capacity,the peak bearing capacity,the elastic and elastic-plastic stiffness,and the ultimate drift angle was obtained.Analysis results indicated that the yield and ultimate bearing capacities all could be improved by increasing axial compressive ratios,longitudinal reinforcement ratios,strength degrees of concrete and sizes of cross sections,however,the confining levels of CFRP stirrups and external wrapped sheets had a little effect on them relatively.Based on the results of parameter analysis,the formulas for key parameters of the resilient model were obtained.In addition,the loading-unloading hysteresis regulation be-tween horizontal force and displacement of FCFRC piers was proposed.Combining the skeleton curve and the hysteresis regulation,a resilient model for horizontal force and displacement of FCFRC piers was presented,simultaneously,compared with the test results,the adaptability of the model was verified.
维普
万方数据