Continuing from: Frame Analysis with Excel – 4, 2D frame analysis
Download Frame2.zip – the download file includes complete open source code.
The solution presented in the previous post in this series made use of the Excel built in functions MINVERSE() and MMULT(), which restricted the size of problem that could be handled, especially in versions earlier than 2007. These functions have now been replaced with a VBA Gaussian Elimination routine, and the matrices are no longer written back to the spreadsheet, so frames with more than 250 degrees of freedom can now be tackled. There is still plenty of scope for improving the efficiency of the solution routine, but nonetheless the present system is adequate for quite large frames, so for the next few posts I will concentrate on improving the functionality:
- Provision for moment and translational release of member ends
- Output of member actions at nodes or intermediate points
- Addition of graphics