摘要
本文采用(FE)有限元方法对腐蚀后的圆形空心t型节点进行了有限元分析。为了保证模拟的准确性，采用有限元模型分别对均匀腐蚀的t型接头和带注浆夹的完整t型接头进行了模拟试验。试验结果与有限元模拟结果密切相关，显示出相似的破坏行为和荷载-位移响应。随后，对56个不同腐蚀程度的t形节点模型进行了数值分析。腐蚀被人为地施加在弦外表面，深度分别为弦厚的10%、20%和30%。模型还考虑了由参数β和γ决定的节理几何形状的变化，其范围分别为0.565至0.678和21至28.此外，还检查了灌浆夹具的性能，包括套筒长度、厚度、强度以及灌浆厚度和强度，与修复复杂性有关。灌浆夹具具有明显的修复能力，使腐蚀接头的极限强度提高了2.23倍。较厚和较长的钢筋大大提高了接头的极限强度。然而，不适当的修补施工会导致荷载-位移曲线突然终止，在加筋弦外出现脆性破坏现象。灌浆夹的附加重量需要合理控制，套筒重叠比应大于0.7.只有在延性破坏的情况下，较厚的灌浆和套管才能有效地提高节点承载力。根据有限元分析结果，直观地分析了注浆夹具对接头变形的约束作用及机理。最后，通过回归分析，提出了修复接头静强度的预测方程。
Abstract
A finite element (FE) analysis of corroded circular hollow section T-joints repaired using grouted clamps is presented in this study. To ensure an accurate simulation, experiments on a T-joint with uniform corrosion and an intact T-joint with grouted clamp are reproduced separately using an FE model. The experimental and FE modeling results correlate closely, displaying similar failure behaviors and load–displacement responses. Subsequently, a total of 56 FE T-joint models with varying degrees of corrosion on the chord, repaired by grouted clamp, were then analyzed numerically. The corrosion was artificially applied to the chord’s outer surface at depths of 10%, 20%, and 30% of the chord’s thickness. The models also account for variations in joint geometry, dictated by parameters β and γ, which range from 0.565 to 0.678 and from 21 to 28, respectively. Furthermore, grouted clamp’s properties were examined, including sleeve length, thickness, strength, as well as the thickness and strength of the grout, in relation to the complexity of the repair. The grouted clamp demonstrated significant repair capability, increasing the ultimate strength of the corroded joint by up to 2.23 times. Reinforcements that are both thicker and longer substantially enhance the joint’s ultimate strength. However, inappropriate repair construction results in an abrupt termination of the load–displacement curve and a brittle failure phenomenon outside reinforced chord region. Additional weight from the grouted clamp requires reasonable control, and sleeve overlapping ratio should be guaranteed to be greater than 0.7. The joint bearing capacity can be efficiently increased by thicker grouts and sleeves only in ductile failure cases. The confinement effect and mechanism of the grouted clamp in joint deformation were visually analyzed as stress distribution from FE analysis results. Finally, a prediction equation is proposed to estimate the static strength of the repaired joint through regression analysis.
NETL
NSTL
Wiley