High Parallel Computing In The Seismic Wave Field Simulation

High Parallel Computing Technology is a popular research field which is applied in almost all kinds of science reaserch and engineering. There are several kinds of Parallel computer as shown below: SMP ( Symmetric Multiprocessor), DSM(Distributied Shared Memory), MPP(Massively Parallel Processor), Cluster. Cluster is a system that used widely nowadays;while at the software level, MPI and PVM are the parallel mode in common use which MPI is a parallel mode based on information-transfering, it is favored for its good agility and good expansibility. Finite element method is one of the effective method which applied in simulation on earthquakes abroad forward modeling, it can apply and adjust complicated physical model and boundary condition, however, large amount of calculation and data should be used and done by using this method. Thus, it is highly necessary to use parallel computing technology into application. United States and Japan are the world leaders in the field of parallel computing technology into application of earthquake engineering, they do lots of research on it. In China, it is few that we do research on this field while we get started late. Research on parallel computing technology and its application of the seismic wave field forward simulation has been done as shown below:(1) study the basic theories and methods.of Parallel method for finite element. do some research in parallel computing methods of equations of the linear equations which commonly used in Finite element method. derive how to use the finite element method to solve the seismic wave equation and gain the linear equations .this provides a theoretical basis for the study of parallel computing research in this area.(2) A parallel cluster is established based on small work stations which provide a platform for the research presented in the paper. WINDOWS operating system is adopted, MPI information-transfering is applied in the whole cluster. Basis concept and theory of Parallel computing and MPI information-transfering model are introduced herein. Basis MPI programming method and related example are given also. Finally, The feasibility of the method has been verified.(3) Research on FEM application of the seismic wave field forward simulation has been done: Wave equations of the ground motion are solved by FEM. Two kinds of Parallel computing Technology are discussed: domain decomposition method and large sparse matrix equation solving. Also, speed up ratio is calculated, feasibility of two methods is verified by analyzing examples by using MPP cluster of super-computer center in institute of engneering mechanics,china earthqake administrator. (4) two-dimensional site model is estabished, finite element model is divided by elements, no-reflecting boundary condition has been discussed by loading earthquake soure into model. Conditions of before and after loading has been compared; three-dimensional site model is established, model is solved by using MPP , simulation results of the ground motion three-dimensional site propagation are given. Related data of its effectiveness is given and verified.