Parallel Algorithm Of Peridynamics For Fracture Problems

In engineering fields,the fracture problem like building collapsed and vehicle damage made people's lives and properties treacherous.In order to keep integrity of the structure during usage,the possible fracture damage must be analyzed during designing progress.Some reliable results can be obtained through experiments.However,destructive experiments cost a lot in large-scale engineering structure.Therefore,numerical method is considered to take replace.Peridynamics is a nonlocal numerical method for solving fracture problems.Due to its nonlocality,the calculation amount is much larger than the traditional local numerical methods.Therefore,it is of great significance to develop efficient algorithms for solving large-scale problems.In this paper,parallel algorithm of peridynamics and its implementation are studied:Firstly,aiming at fracture problems,the peridynamics analysis framework is established.Based on C++,Explicit Peridynamic Simulator(ExPDS)is developed.In preprocessing,different discretization methods are studied.In postprocessing,VTK based result file is designed.In computation cell linked list is introduced into peridynamics in order to speed up neighbor searching and force computation.Contact algorithm in peridynamics is developed for contact and self-contact simulation.Velocity-Verlet method is used to get second order results of displacement and velocity.Secondly,for solving large-scale problems,MPI and OpenMP parallel technologies are introduced into the ExPDS.Cell linked list based domain decomposition algorithm and MPI based communication algorithm for peridynamics is established.Points crossing algorithm is developed for identifying contact on current configuration.A hybrid MPI and OpenMP parallel algorithm is proposed.The main idea of the method is that the computational domain is divided into subdomains and then assigned to several processes,and threads are dynamically created according to the load in process.In order to get higher output efficiency,MPI and VTK based parallel output algorithm is developed.Thirdly,in order to verify the correction,efficiency and ability to solve large scale problem,a set of examples are designed.The correction is verified in static problems,dynamic fracture extends problems and damage problems through tensile block examples,Kalthoff plane example and ice impact example.Regular model and irregular model is used in order to verified the efficiency of the hybrid parallel algorithm.The ExPDS is used to solve a peeling problem with 7.5 million material points,which shows the ExPDS has the ability to solve large-scale fracture problems.