钢筋混凝土梁正截面受弯破坏数值分析

Numerical Analysis of Flexural Failure of RC Beams

基于ABAQUS有限元分析软件对3种配筋率钢筋混凝土梁(RC梁)进行受弯试模拟,重点探究其破坏模式及力学性能的变化规律.模型试验结果显示:少筋梁由于承受拉应力的能力不足,致使梁开裂即破坏,毫无征兆;超筋梁由于主拉应力大于主压应力,导致受压区混凝土突然被压碎致使梁整体破坏.上述二者均属于脆性破坏,工程应用中应尽量避免.适筋梁梁底边缘混凝土率先开裂,钢筋承受拉应力,裂缝逐渐蔓延至受拉钢筋屈服,之后受压区混凝土被压碎,有明显的破坏征兆,既发挥了钢筋的抗拉能力,也发挥了混凝土的抗压能力.

Based on ABAQUS finite element analysis software, three kinds of reinforced concrete beams(RC beams) with reinforcement ratio are simulated in bending test, and the failure mode and change rule of mechanical properties are mainly explored. The model test results show that due to the lack of the ability to bear the tensile stress, the small reinforced beam cracks, which means it is destroyed. There is no sign that the super reinforced beam is destroyed because the main tensile stress is greater than the main compressive stress, which causes the concrete in the compression area to be crushed suddenly and the whole beam is destroyed. Both of them belong to brittle failure, which should be avoided as far as possible in engineering application. The concrete at the bottom edge of the beam with suitable reinforcement cracks first, the reinforcement bears the tensile stress, and the cracks gradually spread to the yield of the tensile reinforcement, and then the concrete in the compression area is crushed, with obvious signs of damage. It not only exerts the tensile capacity of reinforcement, but also exerts the compressive capacity of concrete.