梁端局部无粘结钢筋混凝土梁抗弯承载力研究

为进一步研究梁端局部无粘结钢筋混凝土悬臂梁的抗弯承载力,在理论分析的基础上,使用ABAQUS有限元软件对局部无粘结梁与完好梁的承载力进行了仿真对比分析。结果表明,当局部无粘结梁与完好梁的配筋方式及材料力学性能一致、受拉纵筋锚固良好且可进入屈服阶段时,局部无粘结梁与完好梁的应变分布和应力历程有着明显的差异;局部无粘结梁的极限承载力高于完好梁;随着荷载的增加,无粘结梁的承载机理呈现出明显的“拱效应”。通过梁与拱的共同作用,建立了梁端局部无粘结钢筋混凝土梁抗弯承载力计算公式。

Study on the Flexural Bearing Capacity of Partially Unbonded Reinforced Concrete Beams at Beam Ends

For the purpose of further studying the flexural capacity of partially unbonded RC cantilever beams at the end of beams, based on theoretical analysis, we used ABAQUS finite element software to simulate and to compare the bearing capacity of partially unbonded beams with that of intact beams. The results show that there exist obvious differences both in strain distribution and stress history between local unbonded beams and intact beams under the condition of that the reinforcement mode and material mechanical properties of local unbonded beams are the same as those of intact beams, and the anchorage of tensioned longitudinal bars is good and can enter the yield stage. We also found that the ultimate bearing capacity of local unbonded beams is slightly higher than that of intact beams. With the increase of load, the load-bearing mechanism of unbonded beams presents obvious "arch effect". Finally, through the interaction of beam and arch, the formulas for calculating the bending capacity of local unbonded reinforced concrete beams at the end of beams were established.