Abstract: In rock dynamics calculation, the mesh size has an important influence on the reliability of numerically calculated results. A numerical experimental method is used to research the mesh size effect and its sensitivity mechanism in the numerical simulation of propagation of explosion stress wave in rock. The research results show that a proper mesh size should be specified both by the load characteristics and the property of wave propagation medium. When the number of mesh is up to 16 within one load wavelength, the waveforms and peak values of all calculated physical quantities trend to be stable.The relationships between the values of physical quantities and the different mesh densities are also presented. With the increase in distance from explosive source, the sensitivity of physical quantities to mesh size decreases. This is because high-frequency components attenuate gradually, and the wavelength of load becomes longer with the increase in distance from explosive source. The time step coefficient also has a great influence on computational results. When the time step coefficient equals to 0.05, the stable value of displacement tends to converge.

Key words: ordnance science and technology, numerical calculation, mesh size, time step, sensitivity mechanism