Command Default

By default, assuming a proper filename and extension have been entered, writes the stiffness matrix and right-hand side vector to Jobname.matrix in the current working directory in ASCII format.

Notes

This command copies a matrix from the assembled global matrix file (.full file) or from the superelement matrix file (.sub file) as specified on the FILEAUX2 command and write it in Harwell-Boeing format to a new file named Jobname.matrix. The Harwell-Boeing format is widely used by other applications that deal with matrices.

The assembled global matrix file is created during solution depending on the analysis type, equation solver, and other solution options. By default, the assembled global matrix file is never deleted at the end of solution. For most analysis types, the Sparse direct solver and the ICCG solver will write a .full file. All mode extraction methods used for buckling and modal analyses will write a properly formatted .full file to be used with the HBMAT command. However, when using distributed-memory parallel (DMP) processing, a majority of analyses will write a distributed (or local) form of the .full file which is not currently supported by the HBMAT command.

When dumping the stiffness matrix for transient and harmonic analyses, be aware that the element mass matrix values (and possibly element damping matrix values) are incorporated into the globally assembled stiffness matrix. Thus, the globally assembled stiffness matrix represents more than the stiffness of the model for these analysis types. Please refer to the Mechanical APDL Theory Reference for more details.

When dumping a .full file, the rows and columns corresponding to specified constraints (for example, D commands) are eliminated from the system of equations and therefore are not written to the .matrix file. Also, rows and columns corresponding to eliminated (dependent) degrees of freedom from coupling and/or constraint equations (for example, CE, CP commands) are also eliminated from the system of equations and are not written to the .matrix file. The DOFs that are eliminated from any coupling and/or constraint equations are determined internally by the solution code and may not match what you specified via the CE/CP (or similar) commands.

When dumping a .sub file, the full nxn matrix will be written to the .matrix file for either symmetric or unsymmetric matrices, regardless of whether any of the matrix coefficients are zero-valued. When dumping a .full file, only the lower triangular part of the matrix will be written to the .matrix file if the matrix is symmetric; the full matrix is written if the matrix is unsymmetric. Only matrix coefficients that are greater than zero will be written.

The Harwell-Boeing format is column-oriented. That is, non-zero matrix values are stored with their corresponding row indices in a sequence of columns. However, because the Mechanical APDL matrix files are stored by row and not column, when the HBMAT command is used with a non-symmetric matrix, the transpose of the matrix is, in fact, written.

The WRFULL command, used with the SOLVE command, generates the assembled global matrix file and eliminate the equation solution process and results output process.

The mapping file can be used to map the matrix equation numbers found in the .matrix file directly to the corresponding node numbers and degrees of freedom.

When dumping a CMS .sub file, the last rows/columns of the matrix are non-physical degrees of freedom added internally by the CMS process and cannot be mapped directly to a node number or particular degree of freedom.

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