Dynamics Response Analysis Of Penetration Based On FE-SPH Adaptive Coupling Method

Penetration of projectile into target has broad background in engineering. In thefield of materials science and weapons design and protection, it usually needs toresearch the physical characteristics and response of the materials or structure underimpact loading. In the penetration problems, it is difficult to obtain parameters,involved the deformation, stress and damage by the experiments because the actualprocess is so short. Specifically, numerical method has become an important methodto solve such a large deformation, high strain rate, the dynamics problems.Although a variety of numerical methods were applied to solve the penetrationproblems, but these methods still had some difficulties: methods based on the Eulerianare often difficult to track the material interface and moving boundary; methods basedon the Lagrangian have some difficulties with the distortion elements; a large numberof meshfree methods have a low computational efficiency and accuracy. Therefore, inorder to meet the needs of the penetration problems, we must develop more efficientnumerical methods to overcome these difficulties.Dynamic response of the penetration is studied based on the finite element-Smoothed Particle Hydrodynamics adaptive coupling algorithm (FE-SPH). For theFE-SPH the initial grid is composed entirely of finite elements and the response iscomputed with finite elements until portions of grid become highly strained. Theapproach converted the distorted elements to smoothed particles. FE-SPH algorithmcan allows for the use of accurate and efficient finite elements algorithm in the lowerdistortion regions, and for the use of the SPH method in the higher distortion regions.The main work of this paper is as follows:(1) The basic theory of two-dimensional axisymmetric and three-dimensional FE-SPH adaptive coupling algorithm was studied, and computer program was written. Inthis paper, we studied the traditional algorithms of the finite element and the SPHmethods, and the FE-SPH adaptive coupling algorithm theory, included the criterionof the distorted finite elements into the SPH particles, search algorithm, contactalgorithm and coupling algorithm the element boundary and the particle.(2) Analyzed the computational efficiency and accuracy of the two-dimensionalaxisymmetric and three-dimensional FE-SPH adaptive coupling algorithm. In thispaper, two-dimensional and three-dimensional FE-SPH methods were used to simulate the penetration of the concrete target and aluminum targets experiment. In thenumerical examples, we contrasted three different results from the finite elementmethod, SPH method and FE-SPH method, analyzed the calculating precision andefficiency of the FE-SPH method.(3) The penetration analyses of spaced multi-layered metallic targets aresimulated by the three-dimensional finite element and smoothed particlehydrodynamics adaptive coupling (FE-SPH) method. The approach can effectivelysimulate large deformation, fracture and fragmentation of material, especially fordynamic response analysis of the debris produced by the fragmentations of the targets,which cannot be realized by the finite elements erosion algorithm. The computedresults show that the reasonable layout of the spaced multi-layered metallic target canimprove its protective performance.