OpenSees tools

A collection of OpenSees procedures is shipped with NextFEM Designer, in the file named “procedureXXX.tcl” in the installation folder.

See the manual for pre- and post-processing
See the manual for Response Spectrum analysis library

Response Spectrum analysis for OpenSees
To perform a Response Spectrum analysis based on modal results, use the following command:

dynModal $numModes $spectrum $patternID $comb $csi $dir1 $dir2 $dir3

where $numModes is the number of modes the user wants to combine, $spectrum is the name of the file containing the spectrum points, $patternID is the ID to be given to the load patterns created internally to perform the required linear static analyses, $comb let the user choose whether the SRSS or CQC method should be used, $csi is the damping ratio which is used to calculate the correlation coefficients needed when performing CQC.
The last three parameters ($dir1, $dir2, $dir3), which may assume a value of 0 or 1, are needed to specify the directions associated with the spectrum.

32 bit –

64 bit –

UmfPack2 solver for OpenSees
Beta version. External solver for OpenSees (any version) which improves the integrated UmfPack. Memory and speed improvements up to 70%; no need to set the LValueFact anymore. Tested with OpenSees 2.4.6. Usage inside Tcl scripts:

system umfpack2

32 bit –

64 bit –