锈蚀钢筋混凝土梁抗冲击荷载数值模拟研究

Numerical Simulation of Impact Load Resistance of Corroded RC Beams

为研究冲击作用下锈蚀钢筋混凝土梁的力学性能与破坏模态,通过混凝土梁冲击试验,校核了有限元软件ANSYS/LS-DYNA建立的钢筋混凝土梁结构精细化有限元模型的冲击力时程曲线、跨中位移时程曲线和破坏模态的准确性。在已验证有限元模型的基础上,研究钢筋锈蚀率对混凝土梁抗冲击性能的影响。有限元分析表明:混凝土构件在冲击作用下导致的混凝土剥落程度随钢筋锈蚀率的增加而增加。各冲击高度下的锈蚀钢筋混凝土梁均表现出弯曲破坏特征。钢筋锈蚀对钢筋混凝土构件的抗冲击性能具有一定的影响,在相同落锤冲击高度下,冲击力峰值随钢筋锈蚀率的增大逐渐减小,跨中位移随钢筋锈蚀率的增大而增大。当冲击高度为3.0 m时,锈蚀率为30.0%时的冲击力峰值降低到未锈蚀时的17.9%,跨中位移为增加到未锈蚀时的33.3%。

To study the mechanical properties and failure modes of corroded reinforced concrete beams under impact, the validity of impact force time history curve, mid-span displacement time history curve and failure mode of the fine finite element model of reinforced concrete beam structure established by finite element software ANSYS/LS-DYNA was checked through concrete beam impact test. Based on the verified finite element model, the influence of corrosion rate of reinforcement on the impact resistance of concrete beams was researched. The finite element analysis shows that the concrete spalling degree of concrete member under impact effect increases with the increase of steel corrosion rate. The higher the degree of steel corrosion, the more serious the concrete spalling. All the corroded RC beams at different impact heights exhibit flexural failure characteristics. Steel corrosion has a certain influence on the impact resistance of reinforced concrete members. At the same drop weight impact height, the peak impact force decreases with the increase of steel corrosion rate, and the mid-span displacement increases with the increase of steel corrosion rate. When the impact height is 3.0 m, the peak value of impact force decreases to 17.9% and the mid-span displacement is 33.3% when the corrosion rate is 30.0%.