Numerical Analysis Of Explosion/Impact Response Involved Multiple Materials Using The Material Point Method

The finite element method is main numerical method in solid mechanics, but remeshing and coupling analysis of multi-materials are difficult to solve problems in large deformation, explosion or impact etc. To overcome limitation of the finite element method, Meshless method which is a new numerical method and independent of mesh was developped in recent years. Any materials can be represented by a finite collection of particles with lumped mass, which is the essential feature of meshless method. Not only all information of the continuum body is described, but also deformation, moving and fracture are traced by using these particles. The difficult of remeshing can be effectively avoided. As one of the innovative spatial discretization methods, the material point method (MPM) is an extension of the Particle-in-Cell method and FLIP to solve the problems in solid mechanics. The essential idea of MPM is to take advantages of both the Eurlerian and Lagrangian methods, and the numerical precision and efficiency are satisfied in some problems. The motivation of developing the MPM method is to simulate problems of explosion shock involved multiple materials. The multi-physics interaction, coupling analysis of computation structure dynamics(CSD) and computation fluid dynamics(CFD) are constructed in single domain, which is also main objective in this paper. Some investigations are explored, as follows:(1) Some meshless methods are briefly described, and essential idea and algorithm of the MPM are paied much attentions. The MPM is applied to solve problems of solid stress wave, and numerical solution is consistent with analysis solution. The precision of MPM is validated by this example.(2) The moving and deformation in interface of materials don't need to notice, and the coupling condition is automatically satisfied. The advantage is used to simulate response of multi-layer structure under explosion and impact load, and loading and plastic deformation in every layer material can be computed by MPM. A new numerical method is explored for optimization design of blast/impact-resistant with multi-layer structure.(3) Explosive welding is an instance of slippage detonation. It is very difficult for finite element method to simulate this process. Slippage explosion, deformation of the flyer plate can be described, and detonation pressure or impact velocity can be calculated by MPM.(4) When two types of bombs with case and no case exploded, the concrete wall is destroyed due to effect of blast wave or fragments. A robust numerical method could be supplied for...