钢筋钢纤维混凝土梁柱节点损伤特性及其计算方法

基于低周反复加载试验结果，研究钢筋钢纤维混凝土梁柱节点损伤演化特性。将变形与累积能量耗散指标相结合，建立反复荷载作用下钢筋钢纤维混凝土梁柱节点损伤的计算模型，分析影响钢筋钢纤维混凝土梁柱节点损伤的因素。结果表明：核心区钢纤维体积率、配箍率和轴压比是影响钢筋钢纤维混凝土梁柱节点损伤性能的主要因素；在相同的加载次数下，随钢纤维体积率、配箍率和轴压比的增大，梁柱节点损伤有所减小；其他影响因素相同的条件下,钢纤维体积率为1.0%和1.5%梁柱节点损伤曲线在破坏时的斜率较钢纤维体积率为0.5%的梁柱节点分别减小了21.6%和34.7%；配箍率为0.6%和1.2%的梁柱节点损伤曲线在破坏时的斜率较配箍率为0的梁柱节点分别减小了36.9%和59.4%；轴压比为0.3和0.4的梁柱节点损伤曲线在破坏时的斜率较轴压比为0.2的梁柱节点分别减小了12.5%和17.1%；所建立的反复荷载作用下钢筋钢纤维混凝土梁柱节点损伤计算模型，能够较好反映梁柱节点损伤演化的特点，可用于描述此类节点的损伤演化过程。

Damage property and its calculation method of steelfiber reinforced concrete beam-column joints

Damage evolution characteristics of steel fiber reinforced concrete (SFRC) beam-column joints with reinforcements were analyzed based on the low cycle reversed loading experimental results. A calculating model for damage property of SFRC beam-column joints with reinforcements under cyclic load was established based on the simultaneous usage of the indexes of the deformation and cumulated energy dissipation, and the major effective factors on damage property of SFRC beam-column joints with reinforcements were analyzed. The results show that the steel fiber volumetric ratio, stirrup ratio and axial compression ratio are the major effective factors on damage property of SFRC beam-column joints with reinforcements. Under the same loading cycle numbers, the damage of the beam-column joints decreases as the steel fiber volumetric ratio, stirrup ratio and axial compression ratio grow. As all the other experiment parameters are fixed for the beam-column joints, compared with the steel fiber volumetric ratio of 0.5%, when the steel fiber volumetric ratios are 1.0% and 1.5%, the slope of damage curves at the failure point decreases 21.6% and 34.7%, respectively. Compared with the beam-column joint without stirrup, when the stirrup ratios are 0.6% and 1.2%, the slope of damage curves at the failure point decreases 36.9% and 59.4%, respectively. And compared with the beam-column joint with the axial compression ratio of 0.2, when the axial compression ratios are 0.3 and 0.4, the slope of damage curves at the failure point decreases 12.5% and 17.1%, respectively. The proposed model can reasonably represent the damage evolution characteristics and describe the damage evolution process of beam-column joints.