Simulation of the Damage and Failure Characteristics of Coal under True Triaxial Static–Dynamic Loads

The damage evolution rules for coal under true triaxial combined static–dynamic loads are important to understand and reveal the mechanism of rockburst in mines. numerical simulation was carried out using FLAC3D explore coupling effect static dynamic stress, especially influence load parameters. results show that increase amplitude not only makes plastic zone grow exponentially shortens development time, but also decreases residual strength sample, which leads a much more violent failure. stress wave propagation can be stable sample with frequency time shows synchronous fluctuating features, when is like intrinsic has significant stimulation effect. have different effects on path, weight descending order, namely minimum principal maximum principal, and, lastly, frequency, according entropy method analysis.