Generation of multi-million element meshes for solid model-based geometries: The Dicer algorithm

The Dicer algorithm generates a fine mesh by refining each element in a coarse all-hexahedral mesh generated by any existing all-hexahedral mesh generation algorithm. The fine mesh is geometry-conforming. Using existing all-hexahedral meshing algorithms to define the initial coarse mesh simplifies the overall meshing process and allows dicing to take advantage of improvements in other meshing algorithms immediately. The Dicer algorithm will be used to generate large meshes in support of the ASCI program. The authors also plan to use dicing as the basis for parallel mesh generation. Dicing strikes a careful balance between the interactive mesh generation and multi-million element mesh generation processes for complex 3D geometries, providing an efficient means for producing meshes of varying refinement once the coarse mesh is obtained

Structural analysis of the West Hackbery No. 6 SPR storage cavern

Four separate structural analyses of the West Hackberry No. 6 SPR storage cavern are presented. One analysis covers the creep response of the cavern beginning shortly before the time when an accidental fire occurred and proceeding through the cavern recertification pressure test. The second analysis models the surface uplife that is expected during the same pressure test. The third and fourth numerical studies investigate the structural response of West Hackberry No. 6 to slabbing and a rapid pressure drop. All analyses indicate that this cavern should be structurally stable for the conditions assumed

CHILES 2: a finite element computer program that calculates the intensities of linear elastic singularities in isotropic and orthotropic materials

CHILES 2 is a finite-element computer program that calculates the strength of singularities in linear elastic bodies. A generalized quadrilateral finite element that includes a singular point at a corner node is incorporated in the code. The displacement formulation is used and interelement compatibility is maintained so that monotone convergence is preserved. Plane stress, plane strain, and axisymmetric conditions are treated. Isotropic and orthotropic crack tip singularity problems are solved by this version of the code, but any type of singularity may be properly modeled by modifying selected subroutines in the program

Experimental-analytical comparison of the ductile failure of notched tensile bars

Experimental results of the ductile failure of 7075-T6 aluminum notched tensile bars are compared with finite strain, nonlinear, finite element calculations. This comparison allows the investigation of mean stress dependent macroscopic theories for ductile fracture. Two such theories are examined and the results are presented in graphical form. 14 figures, 2 tables

Experimental aspects of an investigation of macroscopic ductile failure criteria

Experimental results for the ductile failure of 7075-T651 aluminum are presented. Four separate shapes were tested to investigate the importance that macroscopic effective shear stress, hydrostatic stress, and plastic strain play in describing ductile failure of materials. The specimens used were: thin wall torsion tubes to create a state of pure shear, uniform hollow tubes to create a state of uniaxial stress; hour-glass shaped hollow tubes to create a state of biaxial stress; and notched round bars to create a state of triaxial stress. Two proposed ductile failure criteria are discussed in conjunction with the experimental results presented