The Frame4Buckle spreadsheet carries out a buckling analysis of a column or strut, which may be divided into any number of segments with varying cross section details, allowing the analysis of stepped or tapered members. The spreadsheet includes a VBA solver which works well for up to about 20 segments, but becomes very slow for 50 or more segments. Also included is the option to call a much faster external compiled solver, using the ALGLIB library, but this requires the installation of two additional interface files (ALMatrixLib.tlb and ALMatrixLib.dll), and the AlgLib dll file (Alglibnet2.dll). These files are now included in the download zip file: Frame4Buckle.zip, and detailed step by step installation instructions are given at: Frame4; now with added Alglib. The Alglib solver has been tested on systems with 32 bit and 64 bit windows, but not with 64 bit Excel.
Note that if you have already installed the Alglib files to run the Frame4 spreadsheet it is not necessary to change anything. Also if the Alglib files are not installed, or are not working, the spreadsheet should automatically switch to the VBA solver.
Finally, for those with Python and Pyxll installed, I will soon be posting versions of the Frame4 and Frame4Buckle spreadsheets using Python solvers.
In case of any problems with installing the files or running the spreadsheet, please leave a comment here.