聚乙烯醇纤维水泥基复合材料柱恢复力模型

A restoring force model of PVA-FRCC columns

为研究聚乙烯醇纤维水泥基复合材料(PVA-FRCC)柱恢复力模型,以纤维体积率、PVA-FRCC设置范围、配箍率、轴压比及纵筋配筋率为研究参数,对10根PVA-FRCC柱进行拟静力试验。通过对试验数据进行分析,得到退化四线型骨架模型刚度计算方法;根据压弯构件正截面承载力理论,推导出PVA-FRCC柱骨架曲线特征点水平承载力及水平位移计算公式;理论骨架曲线与试验骨架曲线吻合较好,且骨架模型以构件参数表达,实用性较高。采用修正的Park-Ang损伤模型计算损伤指数,并确定了各阶段考虑损伤累积的加、卸载刚度计算方法;结合试验滞回曲线特征及骨架模型,提出PVA-FRCC柱滞回规则。建立的恢复力模型计算结果与试验结果吻合度较高,能较好地表征PVA-FRCC柱在地震作用下的滞回特性。

To study the restoring force model of polyvinyl alcohol fiber reinforced cementitious composites(PVA-FRCC)column,pseudo-static tests were carried out on 10 PVA-FRCC columns with fiber volume ratio,PVA-FRCC setting range,stirrup ratio,axial compression ratio and reinforcement ratio as the research parameters.By analyzing the experimental data,the stiffness calculation method of the degenerate quadriform skeleton model was obtained.Based on the theory of normal section strength of compression-flexure member,the calculation formulas of horizontal bearing capacity and displacement at characteristic points of skeleton curve of PVA-FRCC column were derived.The theoretical skeleton curve is in good agreement with the experimental skeleton curve,and the skeleton model is expressed by the component parameters,which has high practicability.The modified Park-Ang damage model was used to calculate the damage index,and the calculation methods of loading and unloading stiffness considering damage accumulation in each stage were put forward.Combining the characteristics of test hysteresis curve and skeleton model,the hysteresis rule of PVA-FRCC column was proposed.The calculated results of the restoring force model are in good agreement with the experimental results,which can more accurately characterize the hysteretic properties of PVA-FRCC column under earthquake action.