This paper presents the OpenMP parallel implementation of the Distinct Lattice Spring Model (DLSM). The motivation of this study is to reduce the computing time and increase the computational capacity of the DLSM code. Firstly, the basic theory of DLSM is introduced. As an explicit method, the DLSM is very suitable for parallelization implementation. Only a fewcode changes are needed for the OpenMP implementation. Then, the detail parallel design of the OpenMP implementation is presented. Finally, numerical examples are evaluated on quad-core PCs to test the speedup of the parallel DLSM. It is found that a maximum speedup of more than four times is achieved. This means the implementation is successful.
Recently, researchers have realized the importance of the microstructure of rock when studying the macroscopic mechanical behaviors. The experimental methods, e.g., the ultra-bright synchrotron radiation (SR)-CT system (Ichikawa et al, 2001), the scanning electron microscope (SEM) (Wang et al, 2005) and laboratory-based micro X-ray CT (50–500 um) (Flemming, 2007), are used to study the micro-cracking and propagation and time-dependent fracturing behavior of rock and concrete materials. However, the experimental methods are limited by the detection conditions, e.g. CT and SEM are only applicable at low loading rates, it became a barrier of performing further study on the dynamic response on rock materials. Fortunately, numerical methods provide extremely powerful tools for this kind of study. However, in most cases microscopic modeling has very high requirement on the computational capacity of the numerical code and a parallel version is necessary. In this paper, we will discuss the parallel implementation of the Distinct Lattice Spring Model (DLSM) which is a microstructure based method proposed by Zhao et al (2009) and have been used to study the dynamic response of rock materials at microscopic scale (Zhao and Zhao, 2009).