基于扩展有限元的混凝土梁断裂破坏仿真研究

基于扩展有限元方法,模拟不同缝高比以及截面高度混凝土三点弯曲梁断裂破坏过程,构建了混凝土梁荷载-开口位移的数学模型,研究初始缝高比及构件尺寸对混凝土梁应力强度因子以及损伤耗能的影响发展规律。研究结果表明,混凝土梁三点弯曲的荷载-开口位移发展曲线可以分为线性上升、非线性上升与非线性下降三个阶段。混凝土梁抵抗断裂破坏的能力会随着初始缝高比的增大而减小,随着构件截面高度的增大而增强。相同荷载下混凝土应力强度因子会随着初始缝高比的增大而增大,随着截面高度的增大而减小。混凝土梁构件三点弯曲加载过程中的损伤耗能具有明显的三阶段发展演化规律。

Study on Simulation of Fracture Failure of Concrete Beams Based on Extended Finite Element

The simulation of different seam height ratio and section height of concrete beam fracture failure process under three point bending stress was carried out based on extended finite element method.The mathematical model of the concrete beam load-opening displacement was built.The influence of the initial size seam high ratio and component size on the stress intensity factor of concrete beam and the damage energy dissipation law of development was studide.The results show that the load and opening displacement curve of concrete beams under three point bending stress can be divided into linear ascend,nonlinear ascend and non-linear decline in three stages.The concrete beam fracture damage resistance decreases with the increase of initial seam height ratio and enhances with the increase of component section height.The stress intensity factor of concrete will increase with the increase of initial seam height ratio and decrease with the increase of section height under the same load.The damage energy consumption of concrete beam component under three-point bending loading has obvious three-stage evolution regularity.