There was a download of GBTUL 2.0.4.4 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. This free software is a product of Generalised Beam Theory Research Group.
The software lies within Education Tools, more precisely Science Tools. The following version: 2.0 is the most frequently downloaded one by the program users. GBTUL.exe is the most frequent filename for this program's installer. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software.
From the developer:
GBTUL (acronym for “GBT at the University of Lisbon”) is a freeware program that performs elastic buckling (bifurcation) and vibration analyses of prismatic thin-walled members.
You may want to check out more software, such as SatCalc, MathMatic or MemBrain, which might be similar to GBTUL.