Numerical simulation of the fracture process in concrete resulting from deflagration phenomena
Numerical simulation of the fracture process in concrete resulting from deflagration phenomena
复制标题
爆燃现象引起的混凝土断裂过程的数值模拟
DOI：
10.1007/s10704-013-9809-4
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发表时间：
2012
影响因子：
2.5
通讯作者：
D. Fukuda
中科院分区：
文献类型：
--
作者：
Oshiki;M.;Shinyako;K.;Satoh;H.;Okabe;S.;福田大祐;D. Fukuda;D. Fukuda
本文研究了混凝土在爆燃过程中的断裂机理。为此，选用放电脉冲破碎法，以液态硝基甲烷（NM）为爆燃剂。采用这种技术，NM设置在电荷孔内，并通过放电引发。采用Jones-Wilkins-Lee状态方程对NM在钢腔中爆燃产生的压力进行了模拟。模拟结果与实测结果吻合较好，验证了压力模型的适用性。在此基础上，假设混凝土沿预期断裂面沿着可控劈裂，采用二维动态有限元法进行了动态断裂过程分析。结果表明，DFPA预测的断裂模式与实验结果吻合较好。根据控制劈裂的断裂过程，讨论了混凝土在爆燃作用下的断裂机理。由于每个装药孔的应力干涉，在装药孔之间的中间区域上方和下方形成压应力区（CSZ），最大和最小主应力都处于压缩状态。CSZ被认为是重要的，在获得一个更平坦的断裂表面的情况下，控制分裂。总之，所提出的方法被证明是有用的调查的断裂机制的情况下，使用爆燃剂，并可能是有用的设计优化这种控制分裂。
This paper investigated the mechanism of fracture in concrete due to the deflagration phenomenon. For this purpose, the electric discharge impulse crushing method was selected, with liquid nitromethane (NM) taken as the deflagration agent. Employing this technique, NM is set inside charge holes and initiated by electric discharge. The pressure generated by the deflagration of NM in a steel chamber was modeled using the Jones–Wilkins–Lee equation of state. The modeled and measured pressures agreed well and the applicability of the pressure model was validated. Then, assuming controlled splitting along the expected fracture surface in concrete, dynamic fracture process analysis (DFPA) based on two-dimensional dynamic finite element method was conducted. The results showed that fracture patterns predicted in the DFPAs agreed well with those obtained from experiments. The mechanism of fracture in concrete due to deflagration was then discussed in terms of the fracture process in the controlled splitting. Owing to stress interference from each charge hole, compressive stress zones (CSZs) formed above and below the middle regions between charge holes where maximum and minimum principle stresses were both in compression. The CSZs was found to be important in obtaining a flatter fracture surface in the case of controlled splitting. In conclusion, the proposed method was shown to be useful for the investigation of the fracture mechanism in the case of the use of deflagration agents and could be useful for the design optimization of such controlled splitting.