Numerical simulation of stress wave propagating through filled joints by particle model

This paper presents a numerical simulation of stress wave propagation through filled joints using the particle flow code (PFC2D 3.10). A thin layer of granular material without tensile strength is used to model the natural filled joint. The Kelvin viscous elastic contact model is developed with C++ code and embedded as the dynamic link library in PFC2D 3.10 to simulate the particle deformation behavior of the filled joint. It has been proved that the PFC2D is competent in simulating the stress wave propagating through a filled joint according to the comparison between the forward fitting data and the experiment results. The influence of amplitude and frequency on the transmission coefficient is analyzed, and the results show that the transmission coefficient is amplitude and frequency dependent. Additionally, the effect of the tensile stress wave, loading history and filled thickness on the transmission waves is also evaluated. It has been found that the transmission coefficient decreases with the increase of the filled thickness. The tensile stress wave cannot propagate through the filled joint but can tear apart the filled layer, which weakens the multiple reflections in the filled layer. When the incident wave is composed of multiple pulses, the loading history has an important effect on the transmitted waves. For multiple parallel filled joints, the variation trend of the transmission coefficient versus the dimensionless joint spacing is similar to the analytical result obtained by Zhu et al. (2011) except that the loading mode and amplitudes have an important effect on the magnitude of the transmission coefficient. Finally, the deformation process of the filled layer under different loading modes was examined microscopically. (C) 2015 Elsevier Ltd. All rights reserved.