Files cTMOELMX.dat result from finite element discretization of an octant of a cylindrical shell. The ends of the cylinder are free.
The finite element is a facet type shell element (3/4 nodes) with drilling rotation incorporated by the Hughes-Brezzi technique and using the penalty parameter value of G/1000 (regularization parameter) , where G is the shear modulus. In order to improve the coarse mesh accuracy the membrane interpolation is amended by the Allman type quadratic modes linked to the drilling rotation. The bending formulation utilizes the stabilized MITC technique with the stabilization parameter equal to 0.4.
For iterative conjugate gradient type solvers, the problem gets harder when the radius to thickness ratio increases. For quadrilater meshes M1 and using the IC(0) preconditioner, iteration counts are about 100 (for R/t=10) and 180 (for R/t=1000) in reaching the relative residual norm of 10**(-9) depending slightly on the right-hand side vector. For matrices corresponding to triangular meshes the number of iterations doubles in comparison to quadrilateral ones.
Note: The sparsity pattern of the matrix is determined from the element connectivity data assuming that the element matrix is full. Since this case the material model is linear isotropically elastic and the FE mesh is uniform there exist some zeros. Since the removal of those zero elements is trivial but the reconstruction of the current sparsity pattern is impossible from the sparsified structure without any further knowledge of the element connectivity, the zeros are retained in this file.
Matrices are SPD and the data do not contain any RHS vectors.