摘要
采用外贴FRP布加固钢筋混凝土短梁时,现有抗弯承载力计算公式大多基于无下降段的混凝土受压本构模型,导致公式计算结果存在误差。为此,提出将带下降段的Hognestad混凝土受压应力-应变曲线引入计算过程,以考虑受压区混凝土的实际受力状态。根据加固短梁的破坏模式推导了4种破坏形式的抗弯承载力计算公式,包含FRP布未被拉断的适筋破坏、FRP布被拉断的少筋破坏、超筋破坏和剥离破坏,最后通过一批试验短梁数据验证了公式的准确性。结果表明:采用完整混凝土受压本构模型能提供更准确的加固短梁承载力评估值,所推导公式的计算结果与试验结果的平均值为1.03,标准差为0.04,变异系数为4.22%,离散性较小,说明公式具有较好的可靠性。
For RC short beams strengthened by externally bonded FRP sheets,most of the existing ultimate flexural formulas adopt the concrete compression constitutive model without the descending segment.This assumption does not satisfy the actual situation,lead-ing to undesirable calculation errors.Therefore,in this study,the Hognestad compressive stress-strain curve was introduced into the cal-culation procedure,which can consider the actual stress state of concrete.An ultimate flexural formula was deduced according to the four different failure modes of reinforced short beams,including the balanced-reinforced failure mode without FRP rupture,the under-reinforced failure mode with FRP rupture,the over-reinforced failure mode and the debonding failure mode.Finally,the estimation accu-racy of the deduced formula was verified against the experimental data from a group of RC short beams.The analysis results demonstrated that the adoption of the complete concrete compression constitutive model provided a more accurate evaluation on the ultimate flexural capacities of the strengthened short beams.The mean of the ratios between the formula estimations and the experimental measurements was 1.03 with the standard deviation of 0.04.The coefficient of variation was 4.22%showing small discreteness.In conclusion,the de-duced formula has satisfactory reliability in prediction.
作者
杨泽堃
方圣恩
吴应雄
江星
YANG Zekun;FANG Shengen;WU Yingxiong;JIANG Xing(School of Civil Engineering,Fuzhou University,Fuzhou 350108,China;National&Local Joint Engineering Center for Seismic and Disaster and Informatization of Civil Engineering,Fuzhou University,Fuzhou 350108,China;Fujian Rongsheng Municipal Engineering Co.,LTD.,Fuzhou 350011,China)
出处
《南昌大学学报（工科版）》
CAS
2023年第3期254-260,共7页
Journal of Nanchang University(Engineering & Technology)
基金
福州市科技计划项目(2021-Y-084)。
关键词
钢筋混凝土短梁
外贴FRP加固
Hognestad本构模型
破坏模式
抗弯承载力公式
reinforced concrete short beams
externally bonded fiber reinforced polymer strengthening
Hognestad constitutive model
failure modes
ultimate flexural formula
