基于SPH方法对强动载下混凝土结构损伤破坏的数值模拟研究

Numerical predictions of failures in concrete structures subjected to intense dynamic loadings using the Smooth Particle Hydrodynamics method

混凝土结构在冲击爆炸等强动载作用下常常发生开坑和震塌等典型的损伤破坏现象,对损伤破坏的精细化数值模拟依赖于准确的材料模型和合适的数值算法,是当前研究的热点问题.本文首先探讨了基于有限元方法和常用单元删除算法模拟混凝土损伤破坏的内在缺陷和不足,然后基于光滑粒子流体动力学方法(SPH)与作者近期提出的混凝土动态损伤材料模型(Kong-Fang模型)相结合,对强动载下混凝土结构损伤破坏进行数值模拟,得到了实验的较好验证.SPH方法结合Kong-Fang材料模型不需要引入常用单元删除算法中的经验参数,提供了具有较好应用前景的混凝土结构动态损伤破坏的数值模拟方法.

Typical failures such as cratering and spalling are frequently observed on the frontal and distal surfaces of concrete structures when subjected to blast and impact loadings.Numerical predictions of these failures call for an accurate material model and an appropriate algorithm,which is a topic of current research.In this paper,the inherent limitations of the frequently-used finite element method to predict dynamic failures in concrete with the aid of element erosion technique are firstly discussed.Motivated by the natural advantages of the meshfree method to describe the high deformation and large strain situations,the Smooth Particle Hydrodynamics(SPH)method is then combined with our recent KFCW material model to numerically predict dynamic failures in concrete structures.By comparing the numerical predicted failures with the post-test observations of two field tests,it is demonstrated that the SPH method combined with the new material model provides a promising way to predict the dynamic failures without introducing empirical and artificial parameters.