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It is considered a quasistatic elastic-perfectly plastic model contaning the Drucker-Prager yield criterion and the associative plastic flow rule. The problem is discretized by the implicit Euler method in time and by the linear simplician elements in space. The semismooth Newton method is used for solving nonlinear systems of equations. License ( TXT, 35 kB ).
It is considered a quasistatic elastoplastic model contaning the Drucker-Prager yield criterion, a nonassociative plastic flow rule and a nonlinear isotropic hardening. The problem is discretized by the implicit Euler method in time and by the conforming linear simplician elements in space. The code contains an improved return-mapping scheme developped for nonsmooth plastic potentials. Further, the semismooth Newton method is used for solving nonlinear systems of equations. License ( TXT, 35 kB ).
It is based on the FEM and the corresponding linear system of algebraic equations is solved by the preconditioned conjugate gradient method with the additive two level overlapping Schwarz preconditioner. The stiffness matrix for the coarse problem is created by a new aggregation technique. Both Dirichlet and Neumann boundary conditions can be applied. In the second case, arising singular system can be efficiently solved making use of projections. Software package contains two codes. The program AGGREG serves for preparation of an aggregated matrix. The code SOLVER_AG is designed for the parallel solution of large linear systems and is parallelized with the aid of OpenMP. More details ( PDF, 79 kB ), license ( TXT, 35 kB ).
Such systems are subsequently used for testing iterative solvers and preconditioners. The code is characterized by: simplicity and possibility of easy modifications, directly solving model problems on square domains (generalization possible), controlled random coefficient oscillations (stochastic generation of heterogeneity), fast system assembling using vectorization and sparse reconstruction, possible testing of Krylov type solvers with both (block) matrix and matrix free (variable) preconditioners. More details ( PDF, 310 kB ), license ( TXT, 35 kB ).
Carbon dioxide and rock massif. At these days the sequestration of CO2 into deep aquifers (collectors) still remains very actual. The selection of suitable localities for CO2 sequestration is very difficult and exacting problem. Direct experiences of miners from mines, where the miners come into deep natural collectors of carbon dioxide give good information for selection and methodology for surveying of other localities. Therefore the institute published this monograph about the occurrences of CO2 in rock massif in mines in the area of the Bohemian massif. This monograph sums up and documents the natural conditions of occurrences of this gas in mines in rocks or in the coal seams, which are created by means of natural processes.
This model was set up using seismic tomography, and its subsequent visualization and animation starts with the transformation of the measured 3D data. The derived velocity model was applied during the procedure of relocalizing micro-earthquake foci. Submitted to Studia Geophysica et Geodaetica.