This option is used to introduce a geometric imperfection into a model for a postbuckling analysis.
Products: Abaqus/Standard Abaqus/Explicit
Type: Model data
Level: Model
Set this parameter equal to the name of the results file from a previous Abaqus/Standard analysis containing either the mode shapes from a *BUCKLE or *FREQUENCY analysis or the nodal displacements from a *STATIC analysis.
Set this parameter equal to the name of the alternate input file containing the imperfection data, in general, as the node number and imperfection values in the global coordinate system. See “Input syntax rules,” Section 1.2.1 of the Abaqus Analysis User's Guide, for the syntax of such file names.
Set this parameter equal to the step number (in the analysis whose results file is being used as input to this option) from which the modal or displacement data are to be read.
Set this parameter equal to the increment number (in the analysis whose results file is being used as input to this option) from which the displacement data are to be read. If this parameter is omitted, Abaqus will read the data from the last increment available for the specified step on the results file.
Set this parameter equal to the node set to which the geometric imperfection values are to be applied. If this parameter is omitted, the imperfection will be applied to all nodes in the model.
Set SYSTEM=R (default) to specify the imperfection as perturbation values of Cartesian coordinates. Set SYSTEM=C to specify the imperfection as perturbation values of cylindrical coordinates. Set SYSTEM=S to specify the imperfection as perturbation values of spherical coordinates. See Figure 9.3–1.
The SYSTEM parameter is entirely local to this option and should not be confused with the *SYSTEM option. As the data lines are read, the imperfection values specified are transformed to the global rectangular Cartesian coordinate system. This transformation requires that the object be centered about the origin of the global coordinate system; i.e., the *SYSTEM option should be off when specifying imperfections as perturbation values using either cylindrical or spherical coordinates.
First line:
Mode number.
Scaling factor for this mode.
Repeat this data line as often as necessary to define the imperfection as a linear combination of mode shapes.
First (and only) line:
Set to 1.
Scaling factor.
First line:
Node number.
Component of imperfection in the first coordinate direction.
Component of imperfection in the second coordinate direction.
Component of imperfection in the third coordinate direction.
Repeat this data line as often as necessary to define the imperfection.