基于内聚力模型的锈蚀砼梁抗弯刚度

Numerical study on the stiffness of corroded beam based on the cohesive model

粘结性能退化是导致锈蚀钢筋混凝土构件力学性能下降的主要因素之一,基于锈蚀构件粘结性能实验研究成果与内聚力模型,建立了有厚度的双线性内聚力单元与分离式钢筋混凝土梁分析模型,引入粘结界面层,研究了粘结性能退化对锈蚀钢筋混凝土梁抗弯刚度的影响。结果表明,双线性内聚力单元可以有效模拟钢筋与混凝土之间的粘结机制,而根据锈蚀深度确定的有厚度的粘结单元能合理描述锈蚀程度对粘结性能的影响。数值分析结果与实验及经验公式对比,表明了文中方法的有效性和合理性。

Degradation of bond performance is one of the main factors that lead to the decrease of mechanical properties of corroded reinforced concrete members. Based on experimental study of bond behavior of corro- ded components and cohesive zone model, a bilinear cohesive element with thickness was established. A separation reinforced concrete beam analysis model was established and bonding interface layer was intro- duced in this paper to study the bonding performance degradation effect on the flexural stiffness of corroded RC beams. The results show that the bilinear cohesive element can effectively simulate the bond mechanism between steel and concrete. Moreover, the influence of the degree of corrosion on the bond performance can he reasonably described by the thickness of the bonding unit which is decided according to the depth of cor- rosion. Furthermore, numerical analysis results is compared with the experimental data and the theoretical results calculated by experiential method, and the results show that the method in this paper is effective and reasonable.