The paper describes results of a numerical study of the influence of composite structure parameters on the strength and fracture time of brittle materials under dynamic loading. The study is carried out on model concrete samples with different volume fractions of reinforcing inclusions and micropores. Simulation results show that the conventional principle of proportionality of the change in the incubation time of the fracture to the change in the linear dimensions of the fracture region is not applicable when a change in the spatial scale of the region is accompanied by a qualitative change in the parameters of the composite structure. The key factor determining the nonlinear nature of the change in the fracture incubation time during the transition from macroscale to lower scale representative volumes is the factor of phase interfaces, on which primary damage is predominantly localized. This conclusion is confirmed by much more pronounced dependence of the fracture time and dynamic strength of concrete samples on the quantitative concentration of inclusions (i.e. the characteristic distance between zirconia aggregates or micropores) than on volume fraction of inclusions.

本文描述了在动态载荷下复合结构参数对脆性材料的强度和断裂时间影响的数值研究结果。该研究是针对具有不同体积分数的增强夹杂物和微孔的模型混凝土样品进行的。模拟结果表明，当区域的空间尺度的变化伴随着裂缝的质性变化时，裂缝保温时间的变化与裂缝区域线性尺寸的变化成正比的传统原理是不适用的。复合结构的参数。相界面的因素是决定从宏观尺度到低尺度代表体积过渡过程中裂缝保温时间变化的非线性特征的关键因素，主要针对的是局部损害。该结论由混凝土样品的断裂时间和动态强度对夹杂物定量浓度（即氧化锆骨料或微孔之间的特征距离）的依赖性远大于对夹杂物体积分数的依赖性所证实。