混凝土材料动态球形空腔膨胀的数值模拟

Numerical Simulation of Dynamic Spherical Cavity Expansion for Concrete Materials

  • 摘要: 为了验证固体中的空腔膨胀理论,基于混凝土三段式本构模型,用有限元方法对混凝土材料动态球形空腔膨胀进行了数值模拟. 数值模拟结果表明,当空腔膨胀压力超过一定阈值后,空腔边界将以该压力对应的恒定速度膨胀,符合空腔膨胀理论中膨胀压力与边界膨胀速度的函数关系. 进一步分析表明膨胀压力阈值与混凝土强度呈线性关系. 混凝土中空腔边界到弹性波阵面之间的径向应力场分布与理论计算相符,证实了数值模拟的可靠性,揭示了空腔膨胀的物理过程.

     

    Abstract: Cavity expansion in solid is widely employed in penetration resistance analysis. In order to verify the theory of cavity expansion, based on the three-section constitutive model, a finite element analysis of dynamic spherical cavity expansion process for concrete material was conducted. Simulation results showed that cavity wall expands with a certain corresponding velocity when the expansion pressure exceeds a threshold value, which agrees with the functional relation of cavity expansion theory. Further study indicated that the threshold value of expansion pressure linearly depends on the compressive strength of concrete. The radial stress distribution between cavity wall and elastic wavefront agree with theoretical computation, which adds credibility of the simulation, and shows the physical process of cavity expansion in concrete.

     

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