钢筋ECC复合受扭构件的恢复力模型研究

Study on restoring-force model of reinforced ECC members subjected to combined torsion

为了研究钢筋水泥基复合材料(ECC)复合受扭构件的恢复力模型,完成了5个钢筋ECC复合受扭柱在低周反复荷载作用下的试验研究,观察并记录了试验现象。在此基础上,通过试验数据回归分析与理论分析相结合的方法,提出了考虑剪跨比和箍筋体积率等参数的骨架曲线特征点简化计算公式。同时,考虑往复加载对钢筋ECC复合受扭柱性能退化的影响,得出卸载刚度和强度的退化率计算公式,并确定滞回规则。将计算结果与试验结果相对比,计算和试验的骨架曲线基本吻合,说明了本文建议的恢复力模型能够较准确地反映钢筋ECC柱在压弯剪扭作用下的受力破坏过程。

In order to study the restoring force of reinforced Engineered Cementitious Composite(ECC) members subjected to combined torsion,five reinforced ECC columns are tested under axial force and lateral cyclic loading.The loading process is observed and the test phenomena are recorded.On this basis,using combined theoretical and experimental regression analysis methods,a set of simplified computational formula is presented to estimate the T-θ skeleton curves of reinforced ECC columns,while considering influencing major factors such as shear span ratio and stirrup volume ratio.At the same time,considering the influence of cyclic loading on the performance degradation of ECC composite columns,the formulas of the degradation rate of unloading stiffness and strength are obtained,and the hysteretic rules are determined.Compared with the test results,the calculated and tested skeleton curves are basically consistent,which shows that the proposed restoring force model can accurately reflect the failure process of reinforced ECC columns under the action of compression,bending,shear and torsion.