1114 任意の写像型非連続メッシュに対応した三次元有限要素解析手法

Abstract

There is a big issue to generate 3D hexahedral FE model, since a process to divide the whole domain into several simple-shaped sub-domains is required before generating a continuous mesh with mapped mesh generators. In general, it is nearly impossible to set up proper division numbers interactively to keep mesh connectivity between sub-domains on a complicated arbitrary-shaped domain. If mesh continuity between sub-domains is not required in an analysis, this complicated process can be omitted. Usually penalty scheme is applied to set up constraints to keep the continuity between two discontinuous individually meshed sub-domains with different division numbers, however this approach results in an unacceptable rigid deformation in most cases, due to the characteristic on the system of constraint equations. FFGM might accept discontinuous meshes, which only requires nodal information. However it is difficult to choose a reasonable influenced domain in moving least squares scheme with non-uniformly distributed nodes in discontinuous FE models in reality. The blending shape function with refined numerical integration was originally proposed in two dimensional QUAD element by Gupta in 1978,but this approach is originally limited only to 1-iiregular mesh type in three dimensional HEXA element as the work by Morton in 1995. The extension of this function is a promising way, because there are no parameter dependencies. To apply blending shape function to arbitrary HEXA elements in the discontinuous parts of mapped mesh above, element-wise local surface meshing is needed to construct serendipity blending HEXA element. Here a new finite element shape function for discontinuous mapped HEXA8 mesh with element-wise surface-mesh based serendipity hierarchical blending function is proposed to solve the problem mentioned above.