混合配筋偏心受压构件正截面承载力计算理论和方法

Calculation Theory and Method of Normal Section Bearing Capacity of Eccentric Compression Member Reinforced with Steel Bars and Fiber Reinforced Polymer Bars

为完善钢筋和纤维增强复合材料(FRP)筋混合配筋混凝土偏心受压构件正截面承载力计算方法,基于已有钢筋和玻璃纤维增强复合材料(GFRP)筋混合配筋混凝土偏压构件试验,通过试验现象和破坏形态归纳出三种典型的破坏类型,进而分析各破坏类型之间的界限,给出了相对界限受压区高度.利用ABAQUS进行参数分析,得到混合配筋混凝土偏压构件二阶弯矩增大系数表达式,考虑基本假定以及二阶效应的影响,推导了矩形截面偏压构件正截面承载力计算公式.通过对比计算结果与试验结果,发现本文建议的计算公式具有很好的准确性和实用性(试验值与计算值之比N_(u,t)/N_(u,e)的均值为0.99,标准差为0.053),可为混合配筋混凝土偏压构件在实际工程中的应用和推广提供一定的理论指导和设计借鉴.

To improve the calculation method of normal section bearing capacity of eccentric compression member reinforced with steel bars and Fiber Reinforced Polymer(FRP)bars,this study summed up three typical failure types,then analyzed the limit failures among each failure type,and gave relative-boundary compressive region′s height based on several tests of concrete members reinforced with steel bars and Glass Fiber Reinforced Polymer(GFRP)bars under eccentric compression.The second-order moment augmentation factor was obtained through parameter analyses using ABAQUS.By considering the basic assumptions and the influence of the second-order bending moment,the calculation formulas for the normal section bearing capacity of the rectangular section eccentric compression members were derived.By comparing the calculation results with the test results,it was proved that the calculation formulas proposed in this paper had good accuracy and practicability(the mean value of the ratio N_(u,t)/N_(u,e) between the experimental values and the calculated values was 0.99 and the standard deviation was 0.053),which can provide a certain theoretical guidance and design reference for the application and promotion of concrete eccentric compression members reinforced with FRP bars and steel bars in practical engineering.