Set Analysis Options

Form: Analysis Options

This feature is used to set two distinctly different types of options used during analysis:

The "Available DOFs" are the global degrees of freedom that are allowed to be active at every joint in the structure. By default all six degrees of freedom are available (three translational and three rotational). If some degrees of freedom are turned off, they effectively become restrained at every joint, without the need to explicitly assign restraints to the joints. This provides a simple way to restrain a two-dimensional model, for example.

Use this feature carefully! For most models with three-dimensional behavior, all six degrees of freedom should be available. A degree of freedom is available when its associated check box is checked.

This option can be used to specify that an Access database file or Excel tabular file be automatically written every time an analysis is run. The input parameters and output results to be saved, as well as the file name, can be specified.

This feature is particularly useful when running multiple models in batch mode. However, when analyzing different cases in separate runs within the same model, be careful not to overwrite the database file with each run.

Be sure to set the options, as necessary, before each analysis run.

Click the Analyze menu > Set Analysis Options command to access the Analysis Options form and set the analysis options using the following options:

Available DOFs. Check the box next to each degree of freedom (DOF) to be available at every joint in the model. If the DOF is available (box is checked), displacements are possible in that direction at every joint. The occurrence of a displacement at a given joint will depend on the structure, loading, and restraint conditions at the joint. If the DOF is not available (box is not checked), no displacements are possible in that direction at any joint. Effectively, every joint is restrained in that direction.

Fast DOFs. Click one of these buttons to quickly set the six available DOFs to correspond to common structure types.

Automatically save Microsoft Access or Excel tabular file after analysis. Check this box to have the program create a Microsoft Access or Excel file after running an analysis. The remaining parameters described below become available after this box has been checked.

File name. All requested results are saved to this file. Enter the filename and extension in this box. Do not include the path with the filename; the file will automatically be created in the same directory as the SAP2000 .sdb data file. The extension for the filename should be .mdb, .xlsx or .xls. Examples of the filename expected here include MyModel.mdb, MyModel.xlsx, and MyModel.xls. If the filename extension is .xlsx or .xls, the program creates a Microsoft Excel file; otherwise the program creates a Microsoft Access file.
Database Table Named Set drop-down list. Select a previously defined named set from this drop-down list. Database table named sets are defined using the Choose Tables for form. A named set identifies the options selected on that form, and thus defines the type of data to be saved to the file when the Automatically save Microsoft Access or Excel tabular file after analysis check box has been checked.
Groups drop-down list. A Group is a named collection of objects in the model that has been previously defined. Select a previously defined group from the drop-down list to save results for those objects. The built-in group ALL always includes the entire model. All items in the named set, if any, will be saved for all objects in the corresponding group.

Solver Options button. Click this button to access the Equation Solver Options form. Choose the Standard or Advanced Solver. The two solvers perform numerical operations in a different order, and it is possible that sensitive problems may yield slightly different results with the two solvers because of numerical roundoff. The Advanced Solver can be one or two orders of magnitude faster than the Standard Solver for larger problems, and it also uses less disk space. In extremely sensitive, nonlinear, history-dependent problems the difference may be more pronounced. The Advanced Solver is based on proprietary technology that uses, in part, code derived from the TAUCS family of solvers. With the Advanced Solver option, check the Output Mass and Stiffness Text Files check box and then select a case name from the Case Name drop-down list to specify the case for which the stiffness output is to be generated.